The research aims to compare the effect of developing muscle balance on some criteria for evaluating technical and athletic performance and the level of kata performance for karate players. The researchers used the experimental method for its suitability to the nature of the research and its procedures through the experimental design of two groups, one experimental and the other control through the two measurements (pre- and post-). The research sample was chosen intentionally from karate players specializing in imaginary combat (kata) at Al-Rowad Club in Tenth of Ramadan who obtained the black belt in the age group from 16 to 18 years. The sample size was (22) players registered with the Egyptian Karate Federation, and (10) players were chosen from them to conduct the exploratory study, so that the basic research sample became (12) players who were divided into two equal and equivalent groups, one experimental and the other control, each consisting of (6) players. The researchers prepared the proposed muscle balance program according to scientific foundations and reviewed specialized scientific references and previous studies, as the duration of the proposed program was 9 weeks, with 3 training units per week, with a total of 27 training units. The most important conclusions were that the proposed muscle balance program led to a significant improvement in some physical variables and criteria for evaluating the technical and athletic level and the level of technical and athletic performance of the kata (under study), as the percentages of improvement in the physical variables and criteria for evaluating the technical and athletic level and the level of technical and athletic performance of the kata (under study) ranged between (11.57: 43.16) for the experimental group under study. The proposed muscle balance program led to a significant improvement in some criteria for evaluating the technical and athletic performance and the level of performance of the kata under study, as the differences in the percentages of improvement between the experimental and control groups ranged between (5.73: 33.67) under study. The proposed muscle balance program played an effective role in developing the extremity (hand and foot) that is not distinguished in the physical variables and criteria for evaluating the technical and athletic level and the level of technical and athletic performance of the kata (under study).