The purpose of this research was to examine the period that required to improvement the lifestyle by using the HQC technique. Subjects of this research were 160 children who went to the school located in Ubon-ratchathani prefecture in Thailand. The lifestyle improvement using HQC check sheet was practiced for about three months. The change in the ratio of a good lifestyle was examined by χ2-test. 20 items were analyzed, and 12 items were improved significantly. Three items were improved significantly from 3 weeks later and six items were improved significantly from 4 weeks later. From these results, it was suggested that practice for 3-4 weeks or more be effective in the lifestyle improvement that used the HQC technique.
