The purpose of this study was to make clear the influence to salivary melatonin metabolism of children by a long-term camp(31 days and 30 nights). Six healthy subjects(10-11 years old)were participated in the present study which was carried out from July to September, 2007. The saliva was collected three times(6:30 pm:early-evening, 9:30 pm:night, 6:00 am:morning)in five periods(9th-10th days before camp, 2nd-3rd days in camp, 15th-16th days in camp, 29th-30th days in camp, 31st-32nd days after camp). As the result of this study, it was observed that salivary melatonin metabolism of subjects were significantly regulated by a long-term camp. However, one month after the camp, its rhythm was disordered to an average before the camp. From these facts, we reached a conclusion that the building a non-daily living such as camp into a daily living of children was a future practice work.