WASHINGTON -- The government of China and its state-owned companies have sharply expanded their efforts to bolster China's image in the United States, hiring Washington's top lobbying firms and building relationships with state officials from Georgia to Minnesota.

The effort, underscored by a White House visit today by Chinese President Hu Jintao, is aimed at convincing Americans that they should not fear China's rapidly increasing influence around the world, sometimes with controversial partners including Sudan and Iran.

Last year, China's government and its state-owned companies spent at least $4.2 million on fees for lobbyists, lawyers and public relations firms in the United States -- more than four times the amount spent in 2004, according to a Globe analysis of reports filed with the Department of Justice.

Analysts said the Chinese initiatives show the extent to which China is trying to engage, and influence, the levers of power in the United States.

''The Chinese started out not understanding our system . . . but they are moving up rapidly," said David M. Lampton, dean of faculty at Johns Hopkins School of Advanced International Studies and director of Chinese studies at the Nixon Center. ''The Chinese have put enormous emphasis in trying to understand us."

The Center for Public Integrity, a nonprofit investigative organization that monitors the influence of money in politics, says Chinese spending on its public image has risen dramatically over the past eight years.

''We have seen an aggressive effort to raise their profile and to reach out to officials and to the public," said Marina Walker Guevara, a researcher at the Center for Public Integrity who worked on a 2005 study about China's lobbying efforts.

That study found that from 1997 to 2004, China and its state-owned companies spent a total of $5.7 million on lobbying.

The figure increases to $16.5 million if lobbying from Hong Kong, a former British colony that has been returned to China, is included.

Most of the surge in spending in 2005 came from an expensive and sophisticated bid by a Chinese oil company to purchase Unocal, an American oil company.

The Chinese firm, which is two-thirds owned by the Chinese government, paid Patton Boggs, a high-powered Washington lobbying group, $22,000 per month to lobby members of Congress in an effort to convince them that the deal was not a threat to US national security and to support the sale. The firm also paid about $1.4 million in fees to the Washington law firm, Akin Gump Strauss Hauer & Feld, and an additional $760,000 to other firms subcontracted by Akin for similar work, according to lobbying records on file at the Justice Department and a lawyer at Akin.

The Chinese firm ultimately failed to reach a deal to buy Unocal, but political analysts said the lobbying effort marked a new era in China's effort to influence decisions made in Washington and around the world, as China rises to become a global power and the world's second-largest economy.

''China wants to be considered a global power that can weigh in and be listened to," said Elizabeth Economy, a specialist on China's foreign policy at the Council on Foreign Relations. ''This is not a role that it has played historically, and it is not a role that it was interested in playing five to seven years ago."

In addition to lobbying, China has beefed up outreach in other areas, sending its ambassador for informal talks with members of Congress on Capitol Hill that were once considered rare, and bolstering relations with local governments to improve business ties.

China's efforts are paying off. In November, Minnesota's governor accepted an invitation to lead the largest-ever state delegation to China.

In Atlanta last month, a China trade delegation pledged to open Chinese markets to Georgia chicken farmers. The Georgia-China Alliance, formed by a state senator to increase business, has hosted Chinese businessmen and senior members of China's Communist Party.

China, the world's largest communist country, long shied away from the kinds of political outreach common to other foreign governments.

That changed in 1995 after the president of Taiwan, a disputed island that China claims, was allowed to visit the United States and address a pro-Taiwan rally at Cornell University, according to Ezra Vogel, a China specialist at Harvard University.

The visit shocked Chinese officials and convinced them that they needed to do more to advance their interests, Vogel said.

Since then, China's diplomatic efforts in the United States and around the world have expanded to include investments and humanitarian assistance meant to generate goodwill.

''Their biggest goal now is to have a peaceful rise" as a world power, Vogel said.

As China's rapidly-growing economy turns to Latin America for copper and iron ore and to Africa for much-needed oil, China's diplomatic efforts have also increased in those parts of the world.

''You can see China's presence growing very dramatically over the past three to five years," Economy said. ''They send people out in full force, with huge diplomatic and trade delegations to these countries. When they go to Zimbabwe and Brazil, they will come and a sign a hundred different agreements for low-interest loans and educational exchanges. They cause a big splash when China arrives."

China has sent peacekeeping troops to Haiti and the Congo. It also has expanded its outreach into humanitarian efforts, offering aid to the victims of an Iran earthquake and the South Asian tsunami -- contributions that regional specialists said were unusual for Beijing. The Chinese government even flew tents and blankets to the Gulf Coast after Hurricane Katrina.

But China's rising influence around the world still causes concern among politicians and talk-show hosts across the United States.

Despite China's friendly face, its multibillion-dollar investments in the oil industries of Iran and Sudan frustrate international efforts to thwart Iran's nuclear program and a genocidal campaign in Sudan's Darfur region, say some members of Congress.

US Representative Mark Steven Kirk, an Illinois Republican who is slated to meet with Hu today, said that China must do more to cement its friendship with the United States.

''We have found that the official Chinese effort to relate to the United States is better, but it is still far behind other countries," Kirk said. ''China changes its image best when it has good policies that are aligned with the United States."