This paper studies factors that determine salary among professional baseball players in the Asian (Japan, Korea and Taiwan) and US. Empirical results show that US baseball players are the highest paid and those in Taiwan receive the lowest salary, with a large difference of 75 times. Experience, age, education and other variables, as well as population of teams' home cities are influential. Whether or not a player transfers to other teams, their health conditions (measured as BMI) and other variables significantly affect salary, and there is no significant variance arising from different management environments in different countries. Although team age and player salary are correlated significantly in the three countries, the correlation is positive in the US and negative in Asian (Japan, Korea and Taiwan). However, their health conditions (measured as BMI), training, education and population of teams' home cities have insignificantly correlation with the total salary from multi-year contracts.