Introduction: Microleakage is one of the most frequent cause behind a restoration failure. Numerous advancements in restorative materials and placement techniques have been made to overcome this problem. Aim And Objectives: The purpose of this study is to evaluate the microleakage of three different restorative materials with different chemical structure and to determine which among the three has more sealing ability. Materials And Methods: Thirtyextracted mandibular 3rd molars were stored in distilled water and standardized class 1 cavity preparation was done. All the 30 samples were divided into 3 experimental groups GROUP I (GIC), GROUP II (ORMOCER), GROUP III (CENTION N) 10 sample in each group. Teeth were buccolingually sectioned in two halves and immersed in 2% basic fuschin dye and micro leakage was assessed under stereomicroscope. Results: IN our invitro study the highest microleakage was observed in GIC (1.5±0.849) followed by Cention n (0.7± 0.6749) and Ormocer (0.3± 0.483) respectively.Significant difference was observed in group I and group II with p value of 0.0005. Conclusion: Better sealing ability were observed in Ormocer>Cention-n>GIC.