The research aims to study the effect of Cluster Training on developing reactive strength index, change of direction speed and footwork speed for juniors squash under 15 years, The researchers use experimental methodology with two groups design (experimental and control) and pre-post measurements, The research sample was chosen in Purposive method, 12 juniors squash registered in the Egyptian Squash Federation 2018-2019 were divided as follows (6) juniors of the experimental group, (6) juniors of the control group, The researchers add cluster training program ( 9 weeks by three training units per week) as additional training units to the basic program for the experimental group, the results of this study were the cluster training has a positive effect on developing drop jump test variables ( jump height – flight time – contact time – reactive strength index ), sprint , change of direction speed and footwork speed for juniors squash.