Fused compounds of pyrrole and imidazole were synthesized and studied against NS2B-NS3 protease. Fused compound 2 and linear compound 1 show activity against DENV-2 virus and NS2B-NS3 protease. Substituent and its stereochemistry at C-3 position are important for the inhibitory activity. Both of substitution (X) and a linker (Y) affect the inhibitory activity.