Biodiesel is an environmentally friendly renewable biomass fuel.Short path distillation was adopted to remove free fatty acids and pigments from rapeseed raw oil followed by transesterification reaction with methanol in the presence of potassium hydroxide to obtain high quality biodiesel.Better transesterification conditions of rapeseed oil were presented by single factor and response surface methodology analysis.Results show that 94% conversion rate of biodiesel is achieved when reaction temperature 60℃,me...