Abstract: The partial cDNA of FoxO1 was cloned from pig’s liver by RT-PCR, and primer was designed according to the homology blast among human, chimpanzee and rat. Analysis of tissue expression showed that FoxO1 was widely expressed in the liver, lung, kidney, spleen, heart, stomach, subcutaneous adipose, visceral adipose, m.longissimus dorsi and m.quadriceps femoris. Moreover, FoxO1 expressional profile was different between in 1-day-old and 9-month-old pigs following the different developmental stage and tissues. FoxO1 was highest expressed in visceral adipose of 1-day-old pigs while lower in heart and skeletal muscle. Furthermore, FoxO1 had the highest expression in spleen of 9-month-old pigs and significantly higher than piglet that didn’t have complete immunity ability, showing FoxO1 may be involved in body immunomodulation. In addition, the expression profile of FoxO1 not only was significantly different from smooth muscle and skeletal muscle, but also was significantly different from various skeletal muscle of 9-month-old pig. It implied that the expression of FoxO1 is intimately related to skeletal muscle types and exercise intensity.