National security remains a dominant topic in the US-China investment relationship, the report said.

A US judge has yet to rule in a lawsuit by Chinese-controlled Ralls Corp challenging US President Barack Obama 's nullification in September of a deal for Oregon wind farms located near a US Navy weapons-testing facility.

The recent quarter also was marked by controversy generated from a US cyber security firm's claims of hacking by a Shanghai-based military unit. The Chinese government has denied the allegations.

Cui Tiankai, China's new ambassador in Washington, expresse d concern over barriers to Chinese investment in the US. He said he hasn't been persuaded by US regulators' stated reasons for rejecting some deals.

"I'm afraid that will affect investors' confidence," Cui told the Committee of 100, a Chinese American group, last week. "That will, in the long term, turn away some important investors."

The Economist Intelligence Unit recently projected a 50 percent jump in such investment, to $172 billion in 2017 from $115 billion last year.

Cui said the US has historically been a strong advocate of liberalized trade and investment and pressured China to adopt such policies.

"But today it seems that it has been the banner of China. What has been preached to us is not always practised," Cui said, hinting at recent actions that Beijing regards as US protectionism.

There is a misperception that Chinese investment in the US is unwelcome, said Viking Weiqiong Tao, a lawyer with Dallas-based firm Kane Russell Coleman & Logan. She cited the Ralls wind-farm case and an October 2012 congressional report accusing Chinese telecom munications-gear makers Huawei Technologies Co and ZTE Corp of posing a national security threat to the US.