The research aims to study the effect of 3/7 Training on developing some special physical qualities and drop shot accuracy 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 2019-2020 were divided as follows (6) juniors of the experimental group, (6) juniors of the control group, The researchers add 3/7 training program ( 8 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 3/7 training has a positive effect on developing some special physical qualities ( specific reactive agility – muscular strength – muscular power – acceleration - sprint – leg movement speed – dynamic balance ) and drop shot accuracy for juniors squash.