A starting experiment has been conducted to investigate the effect of ignition timing on the starting characteristics for linear engine designed by the research group independently. The fuel injection pulse and ignition timing are controlled by the electronic control unit (ECU) which is developed based on the piston displacement. The combustion characteristics of the engine in starting process are studied based on the cylinder pressure measured by the transient pressure sensor. The result shows that the best ignition timing for linear engine starting is 2.4mm~2.8mm when the fuel injection pulse is 5.4ms and this best region of ignition timing is also meet the requirement of the combustion in the next several cycles.