Combustion characteristics of H2 gas, CNG gas and CNG-H2 hybrid fuel were investigated experimentally in turbulent diffusion flame with co-flowing air stream with swirler. The air velocity changes from slow to high flow rate. Reynolds number is varying throughout the process from laminar to turbulent region. Results showed that the non dimensional flame length decreases with increase the air flow rate and also Non dimensional flame length decreases as decrease in M.F.R. and equivalence ratio. Flame stability increases with increasing the hydrogen content in the hybrid fuel mixture. Flame’s colour for H2, CNG and CNG-H2 were also discussed in the entire experimental work.