The firm expects at least one more institutional investor to join the fund, according to people close to GSR.

GSR had previously said it targeted $50 million to $75 million for the first fund, for which GSR partners will source deals and hold board seats for Mayfield. Kevin Fong of Mayfield serves as an advisor to the firm, which formed in 2004.

The firm, which operates in Beijing as well as out of Mayfield's Menlo Park, Calif., offices, is one of many new China-focused funds raising capital over the past 12 months.

Along with Mayfield, many of Silicon Valley's oldest venture players have also stepped into the China game by sponsoring local teams. Sequoia Capital, for instance, recruited new partners to launch a China fund and recently joined with WestBridge Capital Partners to form Sequoia India. New Enterprise Associates also sponsored Northern Light along with Greylock Partners.

"Twelve to 15 months ago, most of the large institutional LPs were just beginning to figure out whether they wanted to be in China," said GSR Managing Director Richard Lim, who declined to comment on the fund.

For many LPs, the answer is now obvious, and they are looking for sustainable venture funds in China to invest in, said Lim.

GSR has invested in eight companies so far, including Shenzhen State Microelectronics, a company developing chips for the cable television set top boxes, a wireless chip company in Shanghai and Silicon Valley called Mobert, and online dating portals HeiYou and BeiHe.

Lim, along with managing directors James Ding and Sonny Wu and Venture Partner Alex Pan, will invest in four to six deals a year. First rounds will range from $500,000 to $3 million.