As a candidate, Mr. Romney uses China as a punching bag. He accuses Beijing of unfairly subsidizing Chinese exports, artificially holding down the value of its currency to keep exports cheap, stealing American technology and hacking into corporate and government computers.

“How is it China’s been so successful in taking away our jobs?” he asked recently. “Well, let me tell you how: by cheating.”

But his private equity dealings, both while he headed Bain and since, complicate that message.

Mr. Romney’s campaign insists he has no control over his investments since they are held in a blind trust. That said, a confidential prospectus for one of the Bain funds, obtained by The New York Times, promotes China as a good investment for some of the same reasons that Mr. Romney has said concern him: “Strong fundamentals” like manufacturing wages 85 percent lower than what Americans earn, vast foreign exchange reserves and the likelihood that China will surpass the United States as the world’s largest economy.

“Accordingly, Bain Capital expects to see an increasing array of high-growth companies available for investment,” the prospectus says, noting the relative dearth of private equity in China.

Among the companies in which the Bain funds have invested is a global auto parts maker that is in the process of closing a factory in Illinois and moving most of the equipment and jobs to Jiangsu Province, where the Chinese government has built it a new plant; a Chinese electronics retailer accused by Microsoft of selling computers with pirated software; and a Hong Kong-based Chinese appliance maker that was sued for copying another company’s design for a deep-fat fryer.