If you incorporate a company in the US, the US company will be taxed as any other US company based on its formation such as a C or S corporation, limited liability company can be taxed to partner's personal income, and so on. The percentage of the tax will be determined based on the taxable income of the company.
If a Chinese company set up a US subsidary with investement from the Chinese parent company, that means the Chinese parent comapny owns the US company by shares, based on the US-China tax treaty, the Chinese owned US subsidary can get the tax benefit.
If a Chinese company opens an office in the US without incorporating, the office will not be taxed. But if it has any income, the person who operates the business will be taxed. The law will not protect the business entiy. It also involves how to open a business bank account.
The difference concerning these three type of business entities involves the tax issues, legal protection for the business operation and employment arrangement.
If you have any detailed questions concerning setting up a business in the US, you can contact my office or visit my office website at runanzhang.com.
Runan Zhang
Attorney at Law, Tel: 202-965-4348