The objective of this work presented here was focused on analysis of in-cylinder combustion characteristic, engine performance, and nitrogen oxides emission characteristic from marine gas oil for propulsion diesel engine of naval vessels and biodiesel with fuel injection timing in a single cylinder diesel engine. In addition, combustion process was analyzed with a high speed camera of marine gas oil and biodiesel fuel. Retarding the fuel injection timing from $BTDC25^{circ}CA$ to $BTDC5^{circ}CA$, in cylinder peak combustion pressure was gradually decreased, however, engine torque showed a tendency to increase. The highest nitrogen oxides level was measured at $BTDC15^{circ}CA$, they were reduced at retarded and advanced condition on the basis of $BTDC15^{circ}CA$. Comparing with combustion process of marine gas oil and biodiesel fuel at $BTDC5^{circ}CA$, self-ignition timing of biodiesel fuel included oxygen content was faster than marine gas oil, however, a cautious observation indicates a slightly higher flame intensity for marin gas oil than biodiesel as a diffusion flame is developing.