The purpose of this study was to compare the marginal leakage of resin liner which was used as a liner to amalgam restoration. Control group composed of no liner group, copalite group and experimental group composed of All-bond 2, Vitrebond, Superbond D-liner applied groups were evaluated. Cl.V preparation with a size of $3{ imes}2{ imes}1.5mm$ on 70 extracted primary molars were made and applied appropriate liners for each groups. After amalgam filling and polishing, polished specimens underwent temperature changed from $5^{circ}C;to;55^{circ}C$ a thousand times. After thermocycling, specimens were placed in 2% methylene blue dye solution for 72 hours in an incubator set at $37^{circ}C$. The teeth were sectioned buccolingually and the degree of dye penetration was observed with a spectroscopy. (${ imes}30$) The following results were obtained. 1. Vitrebond, All-bond 2, Superbond D-liner group exhibited a statistically significant lower degree of dye penetration than no liner and copalite group. (Kruskal-Wallis analysis, P<0.05) 2. No liner group and copalite group exhibited a similar degree of dye penetration. (Mann-Whitney analysis, P>0.05) 3. All-bond 2 group exhibited a statistically significant lower degree of dye penetration than Vitrebond group, (Mann-Whitney analysis, P<0.05) Superbond D-liner group also exhibited a lower degree of dye penetration than Vitrebond group but was statistically insignificant. (Mann-Whitney analysis, P>0.05)