Abstract: In the paper charge loss cross sections for muliti-charge carbon ions by collision with neutral hydrogen or helium atoms been investigated. Meanwhile electrical potential functions and electron momentum distributions for multi-charge carbon ions have been calculated as well by using binary encounter and Thomas-Fermi approximations. Charge loss section data for multi-charge carbon ions accord well with those of Shirai’s results. The formulae used here and computetional programme developed can be applied to any multi-charge ions, and there is some universility in them.