Body shape has an important role in playing basketball. The position of players in basketball can be determined by their height. There is some information that can be inferred from height. Body mass index, the ratio of leg to body length, and the ratio of arm length to height. This is valuable information for extracurricular coaches because they can find out if a player has the ideal body shape as a basketball player. Through this research, it can be seen the body shape of the basketball extracurricular participants in the junior high school category. This research also helps extracurricular trainers to identify extracurricular participants who have the ideal body shape. The method used in this research is a survey using a measuring tape, measuring height and weight. The samples involved in the study were 104 boys and 48 girls with an age range of 12-15 years. The measurements taken were height, weight, arm span, and sitting height. The measurement results show that 55% have an ideal height, 34% have a normal body mass index, 5% have an ideal leg length, and 99% have an ideal arm span. Basketball extracurricular participants at private junior high schools in Sukoharjo have the potential to be hampered in performing movements using the legs and potentially easier to perform movements using the arms.