The purpose of this study was to compare the wear resistance of heat pressure-cured microcomposite(SR-Isosit-N), photo-cured microcomposite(Dentalcolor), unfilled heat-cured resin(Thermojel) and that of human enmel. Specimens were made with specially designed die and finally polished with #3,000 diamond paste. After 100,000 strokes of tooth brushing at electric tooth-brushing machine, mean thickness loss of each specimen was measured by using surface profile and integration. The results were as follows 1. Mean thickness loss were $84.3{pm}27.3{mu}m$ in unfiled heat-cured resin, $9.4{pm}2.5{mu}m$ in photocured microcomposite, $7.6{pm}2.1{mu}m$ in heat.pressure-cured microcomposite and $0.97{pm}0.42{mu}m$ in enamel. 2. Heat.pressure-cured microcomposite and photo-cured microcomposite had no difference in mean thickness loss(p>0.05). 3. Unfilled resin and microcomposite had much differences in mean thickness loss (p<0.005). 4. ha resins used in this experiment had too much mean thickness loss as compared with enamel (p<0.005).