Whether you need a visa to visit another country depends almost exclusively on what passport you hold. For example, if you hold a Chinese passport and want to visit USA, you would need a visa to do so. The same applies to Chinese passport holders who want to visit Canada. A visa is required.
There are three useful websites that will help you to easily determine if you need a visa to visit any country in the world based on which passport you hold. On these websites, which appear below, you simply choose the country whose passport you hold as well as the specific country that you intend to visit.
U.S. Lawful Permanent Residents are visa exempt if visiting Canada, Mexico, or Bermuda.
While a Chinese passport holder requires a visa to visit Canada, an exception exists if the individual is a lawful permanent resident of the United States. Accordingly, permanent residents of the U.S. may use their "green cards" in lieu of obtaining visas when requesting to enter Canada, Mexico, and Bermuda. A "green card" does not exclude permanent residents from obtaining visas to visit countries other than Canada, Mexico, and Bermuda. Even though a “green card” does not exempt its bearer from obtaining a visa if otherwise necessary (except for visiting Canada, Mexico, and Bermuda), it may be necessary to display the green card when applying for a visa at a Consulate inside the U.S.
If you are a U.S. lawful permanent resident and have questions about visa requirements for visiting other countries or general questions about foreign travel, speak with your immigration attorney.