Objectives : The purpose of this study was to examine the awareness of mothers on their children’s oral health and their concern for that by socio- demographic characteristics and the relationship of their awareness of methods of dental-caries prevention to their practice of the methods. Methods : The subjects in this study were 337 guardians of preschoolers at kindergartens and daycare centers. A self-administered survey was conducted from April 25 to May 27, 2011, and the collected data were analyzed by the statistical package SPSS 18.0. Results : 1.Self-rated concern for children’s oral health, 87.7 percent and 12.1 percent replied,“ So-so.”Whether they were working or not and whether they were mainly responsible for child rearing made significant differences to that(p<.05). 2. As to subjective awareness of their children’s oral health, the largest group of the mothers answered“ So-so.”(44.9%) The second replied that their children were in good oral health(40.5%), and the third group in poor oral health(14.2%). 3. The relationship between self-rated concern for their children’s oral health and awareness of methods of caries prevention, statistically significant differences were found according to toothbrushing education and sealant(p<.05). There were no statistically significant differences in practice ,but application of fluoride was the least. 4. The relationship between self-rated awareness for their children’s oral health and awareness of the preventive methods of caries, there were statistically significant gaps in awareness of toothbrushing education(p<.05). In practice, statistically significant gaps were found in practice of toothbrushing education and sugar-intake restriction(p<.01). 5. In regard to the correlation between awareness and practice of the preventive methods of caries, awareness of all the factors involving toothbrushing education, sealant, application of fluoride and restriction of sugar intake had a significant positive correlation to practice of them. Better awareness led to better practice. Conclusions : In order to ensure children’s successful oral health care, more authentic education of how to prevent dental caries should be offered by experts such as dental hygienists and dentists. Especially, detailed information on application of fluoride, restriction of sugar intake and pit and sealant should be provided for mothers to help their children to stay away from dental caries.