Jet-impinging diffusion flames were produced and experimentally investigated. The impinging mechanism can enhance the turbulent fluctuations and increase the combustion efficiency greater than that in a single jet flame. Results show that the temperature profiles are consistent and less related with the impinging angles as the Reynolds numbers become greater than 180. The impinging flames exhibit an axial symmetrical column flame at a 45degrees impinging angle due to the flame stretch effect. When increasing the impinging angle to 72 or 90degrees, the radial flow momentum after the jet-to jet impingement may stretch the flame into a nonsymmetrieal shape. The impinging flame was exciting with pulsation to further enhance the mixing rate. Results show that pulsation induces both large and small impinging flame structures. The larger scale structures increase the oxidizer entrain flow to increase the mixing rate. Coupling with the small scale in the flow structure, the pulsation flame obtains higher combustion efficiency and a stable flame.