This study was intended to analyze the relationship between shoulder joint torque and ball speed for 12 professional baseball pitchers using the uniform velocity instrument(Cybex 6,000). Subjects were divided into the 2 groups that were A(high speed) and B(low speed) group. Based on the results of analysis, the study was conducted to identify uniform-velocity exercise ability and ball speed. Statistical analysis was performed using analysis of variance student`s t-test. The study results are as follows: It was show that there was not a statistically significant difference between uniform-velocity exercise ability in the group A(high speed) and the group B(low speed) in relation to the internal side and external side, but the group A was high in every angle velocity except 60 degree/sec of the non-dominant side Conclusionally, based upon the above results, the difference between the pitcher`s ball velocity and uniform-velocity exercise ability could be found, and in particular the effect of the internal torque on the velocity be found.