It is conclusion that we studied 428 elementary boy students about physical growth and fitness development. Their ages is from 9 to 12. 1. Characteristics of physical form The rapidity of physical growth is higher around 12 years old. It seems that they grow more ralidly by one year than they did ten years ago. The volume has developed after 11years old. The girth and diameter is fast around 11 years old. there is some difference in each age. Besides as students grow all of the varies is getting increased. 2. Fitness Development The fitness has many difference in grip strength, bent twist and touch, grass drill, sit and reach, 50m dash, sit -ups standing long jump and endurance run. It seems that the students has developed the fitness of strength, power, muscular endurance and speed, as they are getting old.