Abstract: The flexural strength of carbon black-filled epoxy resin was analyzed as a function of their volume content ratios. Carbon black filled epoxy specimens have enhanced flexural strength in comparisons with pure epoxy. In this paper we have made 5wt%, 10wt%, 15wt% of carbon black fillers added to the epoxy in various sizes such as 50μ, 100μ, 150μ. Flexural specimens were made as per ASTM D790 and tested in universal testing machine (utm) through three point bending test. Various results obtained were tabulated and optimized that 15wt% of 50 μ size carbon black fillers provide the best flexural strength.