SMEs　in　Japan　had　played　a　major　role　for　development　of　Japanese　modem　economy　especially　after　World　War　II,　and　SME　policies　had　supported　activities　and　growth　of　these　SMEs.　There　is　a　best　SMEs　policy　supporting　system　in　Japan.　It　is　aiming　at　assisting　SMEs,　which　face　much　difficulty　in　spite　of　their　self-efforts　to　solve　problems.　In　concrete,　their　policy　mainly　consisted　of　financing　support,　technology　support,　managerial　support,　taxation　support　and　so　on.　It　ensures　that　the　SMEs　are　the　driving　force　of　economic　development.　Studying　the　policy　supporting　system　in　Japan　can　provide　China　with　useful　inspirations　concerning　the　solution　to　the　problems　of　SMEs　development　in　China.