The purpose of this study was to examine the effect of variable practice and rate of practice trials on acquiring, learning and transferring of volleyball service in children. Forty students (11.2 y) were assigned randomly in two similar variable and constant practice groups. During the practice phase, each participant in both groups completed 450 trials. After each 150 trials one retention and one transfer test conducted. Data analyses were conducted with t-test and ANOVA. The results indicated that increasing the number of trials in acquisition gives rise to learning in both retention and transfer stages (p=0.001). But the effect of practice type in retention stage was not seen (p=0.19), while in the transfer test was (p=0.004). The present research suggests that when the aim is acquiring the pattern of skill the constant practice is more effective, because the increase of exercise (increasing the number of trials in acquisition phase), will result in more differences between two groups. But when the practice scheduling aimed at parameterization, the variable practice was useful.