Objective: To compare the cost-effectiveness of ART (atraumatic restorative treatment) with that of resin sealant in caries prevention for primary school children. Methods: Two hundred and twelve children aged 7-9 years old took part in this research. One molar of every child on 1 side of the mouth was sealed with light-cure resin sealant (Concise, 3M) and 1 on the opposite side with chemically firmed glass ionomer (Ketac-molar, ESPE). The time allowed for application, the amount of materials of all kinds needed and times for repetition of the process due to failure were recorded. The remaining amount of sealant on the teeth was checked in the eighth month after treatment. Results: The results indicated that time for application, cotton rolls and number of repeated applications of the sealant were respectively 3.54 minutes, 2.52 and 0.04 times and for ART 3.18 minutes, 1.13 and 0.03 times. As far as the material itself was concerned, the glass ionomer used in ART was more expensive than resin sealant: 3.77 compared with 0.93 Yuan. Howeve,r the cost of additional equipment needed for the sealant method was much higher than for ART. Furthermore, there was no significant difference between sealant and ART in durability. Conclusions: The results suggest that ART is more cost-effective than sealant in caries prevention.