Aim: The purpose in-vitro study was to compare the antimicrobial effect of four different sealers (zinc oxide/ eugenol based sealer, resin based sealer, Ca(HO)2 based sealer and new copiba oil resin based sealer).2.Evaluate the solubility of the four different types of tested root canal sealers. Materials and Methods:in this study we tested four differernt types of sealers 1-resin based sealer(ah26)2-zinc oxide based sealer (caryosan n)3-calcium hydroxide sealer(crcs)4-newly introduced resin sealer(copiba oil )have been evaluated by for antibacterial activity using agar diffusion method and solubility.by using fresh mix of each sealer. Results: The results of the antibacterial test showed that the Copaiba oil resin sealer was effective with agar diffusion test, where an inhibition zone was noticed when compared with the other sealers tested. Solubility results showed that the AH26 resin sealer was the least soluble sealer followed by Copaiba oil sealer and Zno based sealer, while CA (oh)2 based sealer (CRCS) was the most soluble sealer. Conclusions: Within the limitations of this in vitro study, the following conclusions have been drawn:1-Copaiba oil resin seems to be promising sealer compered to Zinc oxide based sealer and calcium hydroxide based sealer regarding its solubility and antibacterial activity2-Agar diffusion tes twas simple and effective methods for testing antibacterial effect of different types of sealers.