In this paper, it is examined the optimum release conditions in javelin throwing considering to be thrown by human. Three types of javelin is thrown by seven javelin throwers. These subjects in throwing are videotaped using high speed video camera at 200 fps. The behavior of the javelin is analyzed considering the deflection of the javelin at release.
　These results are as follows ;
　Throwing distance is longer than the theoretical throwing distance calculated from release velocity, height of release and release angle.
　Throwing distance is longer as release velocity is higher, it seems that there is a tendency the rate of change in a proportion. Height of release is roughly the same value in each thrower, and affected from height and throwing skill of thrower. Release angle to maximize release velocity is calculated, the value is different in each thrower, and it is suggested that it is the only way to measure optimum release angle in javelin throwing.
　The optimum values to maximize throwing distance are calculated, there are 35.2 deg in attitude angle, 0.6 deg in angle of attack, and -3.2 Nm in pitching moment. To discuss the optimum release conditions, it is necessary to regard that most of these parameters affect each other.

DESCENTE SPORTS SCIENCE Vol.17/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE