California, which has more immigrants than any other state, has seen increasing immigration in the last decade from China, which has overtaken Mexico as the top sending country.

According to a US Census study on place-of-birth composition of immigrants in May 2015, the United States had 1.2 million immigrants in 2013, and 147,000 of them were from China, followed by India with 129,000 and Mexico with 125,000.

Immigrants as classified by the Census Bureau's Population Estimates Program are those foreign-born residents whose domicile one year ago was abroad, including overseas students and undocumented immigrants.

Last year, 33,000 immigrated to California from China, compared with 30,000 from Mexico, according to the Sacramento Bee newspaper, which cited data from the Census Bureau and Public Policy Institute of California.

Observers said Chinese immigrants in California largely concentrate in the technology industry due to strong demand for highly skilled workers, especially in Silicon Valley.

"Immigrants may be attracted by a combination of higher wages and opportunities for professional development," said Petra Moser, an associate professor of economics at the New York University School of Business. "As the number of Chinese workers find employment in Silicon Valley, social and professional networks facilitate the transition and help to attract more workers."

"We have seen a steadily increasing number of highly skilled immigrants from China in recent years," said Rei Teng, a lawyer with Immigration Law Group, a San Jose, California-based firm.

"A small part of the applicants are Chinese students who graduated from US colleges and decide to stay, and the majority are transferred employees from the Chinese subsidiaries of US multinationals," said Teng, whose corporate clients include major high-tech companies in Silicon Valley.

Many companies have set up operations in China in the past few years due to China's economic growth, she explained.

Immigration programs, such as the H1-B visa that allows US employers to hire foreign professionals in special occupations, have been criticized for taking away Americans' jobs. But Moser said both Silicon Valley firms and the state could benefit from it.

"Silicon Valley firms gain as skilled immigrants meet their demand for high-skilled workers, which could not be easily met by the local population," she said. "As a state, California gains through the growth of these firms, especially because the costs of the education that these workers bring were not borne locally by California's education system."

She said the benefits were purely economic, though the rapid growth of Silicon Valley

liazhu@chinadailyusa.com