A mixed fuel consisting of gaseous fuel and liquid fuel can realize flash-boiling injection under in-cylinder condition close to top dead center. In this study, liquefied ethane was mixed into gas oil. Ethane has high vapor pressure and can facilitate flash boiling while it is easy to be liquefied by pressurization. This mixed fuel applied into diesel engine and the performance and exhaust emissions were examined in a single cylinder test engine. As a result, the flash boiling effect enhances spray atomization and evaporation to promoted lean mixture formation, and achieved low soot and low NOx combustion without EGR while improving thermal efficiency. In addition, effect of multiple injection was also tested for reduce the maximum pressure rise in combustion.