Plyometric training is an effective mode of training that is important for a soccer player in order to enhance their physical fitness. The purpose of this study was to investigate the effect of three month in-season Plyometric training on leg power, agility and speed performance of Dangila kenema football club players. The study was focused on an experimental study. For this study the researcher had only one group which is consisted of 20 soccer players who aged 20-25 from the total population of 24 players of the club, but the remaining 4 players excluded in this study due to injury problem, available sampling techniques were used to select all samples. In addition to the normal technical and tactical training the subjects were took part a basic Plyometric training program 2 days/week for 3 months under the control of the researcher. Power, agility and speed were the three basic physical fitness variables that were selected for this study. Tests were taken and collected from the participants, pretest before the beginning of Plyometric training and posttest after they took12 weeks consecutive training. Then the collected data were analyzed by using SPSS software version 23 and comparison of mean was done by Paired sample T-test The MD of speed, agility and power were 0.12, 0.27 and -6.35 respectively, with P<0.05. The results obtained in this study showed that Plyometric training had a significant improvement of power, agility and speed of the players by increasing the height they jump through vertical jump test and reduced the time they cover under Illinois agility and 30m speed test after posttest. Generally the study concluded that in- season Plyometric training can be an effective training technique for the improvement of a soccer player’s leg power, agility and sp