Abstract: A new method of attitude determination using two satellites is presented inthis paper, that is to determine vehicle's attitude using carrier phase of two earthsynchronous satellites. The principle and the precision of attitude determinationusing two satellites are discussed in detail in this paper. Computer simulation statethat the mean square error of attitude determination using two satellites can be0.23° in yaw, 0.18° in pitch and 0.15° in rolling, under conditions of mean squareerror of carrier phase single difference be 0.02 cycle, antennas be 1 meter apart, andso on.