This paper deals with a compliant foil gas thrust bearing. The performances of thrust sectors for three radius ratio, namely, 0.3, 0.5 and 0.7 are evaluated respectively. The geometry of thrust sector with radius ratio 0.3 and 0.7 is optimized. The results of calculation are offered in graphic form for the sake of convenient use in the bearing design. The effects of various variables on bearing behavior are analysed. A test apparatus and several experimental methods for the bearing are described. The results of calculation and experiments are compared. Finally, some examples to explain how to use the graphs are given.