Objective: To evaluate the outcome of a health education program on sedentary behavior among primary and secondary school children through Transtheoretical Model.

Methods: Five primary schools and four middle schools were selected and students from grade 3 to 5 in primary schools and grade 1 to 2 in middle schools were selected to take part in the program, as control and intervention groups respectively. Corresponding intervention measures were provided to the intervention group, with phase, process and level of changing on sedentary behavior measured for both groups during the follow-up period. Comparison to the above items on the two groups was measured statistically.

Results: Behavior among the intervention group was gradually changed regarding: phase contemplation, preparation and maintenance, with the proportions in phase action and maintenance higher than the control group. After carrying out of intervention programs, the sedentary time on weekdays between the two groups did not show significant differences. However, the sedentary time on weekends of intervention group was (2.53 ± 1.62) hours, significantly lower than the hours from the baseline survey (2.84 ± 1.82) and the control group (2.78 ± 1.72) respectively. During the follow-up period, the average score of intervention group in the changing process was (2.98 ± 0.77), higher than the control group (2.80 ± 0.81). At the same time, the average score of intervention group in the process of changing, decisional balance (pros) and self-efficacy were 2.98 ± 0.77, 3.06 ± 0.75 and 3.13 ± 0.72, respectively, all higher than data from the baseline survey. In the control group, the process of changing and the average score on self-efficacy had improved.

Conclusion: The corresponding intervention program seemed to have played a significant role among the school-aged children on their sedentary behavior during the weekend but no significant difference was found in the weekdays.