When the spermatozoa of oligoasthenozoospermic patients were suspended with the supernatant of normal semen, an increase in triple ATPase enzyme activities besides enhancement of spermatozoa motilities were observed. This suggests that factor or factors present in the supernatant of normal semen that effects spermatozoa motility also have a positive effect on triple ATPase enzyme activities. In an attempt to produce such an effect, zinc, arginine and fructose were added to the incubation media where the spermatozoal ATPase enzyme activities were determined. Zinc increased Ca2+-Mg2+ ATPase enzyme activity without affecting Na+/K+-Mg2+ and Mg2+ ATPase activities. Triple ATPase enzyme activities remained unchanged after arginine and fructose additions. As a result zinc is thought to be one of the factors that affect spermatozoa motility in seminal plasma.