The physical activity level and health-related physical fitness were investigated in 196 males and 153 females aged between 15 to 65. Physical activity level was assessed by Lipid Research Clinics (LRC) physical activity questionnaire and classified into four groups:highly active, moderately active, low active, and very low active. Body mass index, one minute sit-ups, sit-and-reach and 3-minutes step test were conducted to evaluate physical fitness components: body composition, muscular strength and endurance, flexibility, and cardiovascular endurance respectively. The results indicate that the physical activity level of the subjects was relatively low as compared with data from other countries. In comparing subjects within the same age group, subjects with higher physical activity level appeared to have a posititve significant difference from their less active counterpart in cardiovascular endurance (male: age group 10-19) and muscular strength and endurance (male:age group 20-29; female:age group 10-19). In conclusion, subjects were shown a pattern of less active lifestyle. This is especially crucial for younger age groups in the development of physical fitness. A Call of action is needed to make improvement in physical activity level to the population in Taiwan as a whole.