The main aim of the study was to assess the heath-related physical fitness in Indian school children. For this purpose, a cross sectional purposive sample of 437 male children into seven age groups i. e. 12 (N=63), 13(N=59), 14(N=63), 15(N=63), 16(N=63), 17(N=63) and 18(N=63) years belong to middle (N=215) and higher secondary (N=222) schools. The random sampling method was employed for the purpose of data collection from various schools running in the tribal region of Sarguja division in the state of Chhattisgarh. For estimated body fat percentage of an individual, two skin-fold sites i.e. triceps and sub-scapular were measured by standard Skin-fold Caliper of all the male subjects in millimeters. The measurements were made while the children were wearing light clothes and no shoes. Health-related physical fitness was assessed through the sit-and-reach test for flexibility, modified sit-ups test in one-minute for strength/muscular endurance and nine-minute running/walking test for cardio-respiratory endurance. The subjects were tested within one month of their birthdays. All the subjects were tested in AAHPER health related fitness test items i.e. 1.5 mile run, modified bent knee sit-ups for one minute, sit and reach test and triceps and sub scapular skin folds to collect the data on cardiovascular endurance, strength and endurance of abdominal muscles, flexibility of back and hamstring muscles and amount of fat. From this study, it was concluded that the health related fitness of boys of twelve to eighteen years of age of Sarguja division declined in all age groups on flexibility with advancement of age except fifteen years of age and inclined in all age groups on abdominal strength/muscular endurance and body composition with advancement of age. Which, possibly, may be attributed to the lack of physical activity after the age of fifteen years. They unproved in cardio-respiratory function at twelve to fourteen years of age and later on, they improved significantly up to the age of eighteen years with some fluctuations in time.