How many countries built the International Space Station?

United States (NASA), Russia (RKA), Japan (JAXA), Canada (CSA) and eleven European countries (ESA). The Brazilian Space Agency (AEB) participates through a separate contract with NASA. The Italian Space Agency similarly has separate contracts for various activities not done in the framework of ESA's ISS works (where Italy also fully participates). Chin has reportedly expressed interest in the project, especially if it was able to work with the RKA, although as of 2008 it is not involved.

So 75 Countries In Total. The main countries that do use it are Canada, USA, China, Russia, Brazil, Afganistan, Iran, and most middle eastern countries. Including Japan, Braqzil and Nubia.