In the present study, experiment on the evaporation of pure water droplet on heated surface was conducted, and the evaporative heat transfer coefficients were calculated from experimental results. The pure water droplet of about $10{mu}l$ was applied onto the heat transfer surface, then the shape of the droplet was analyzed during the evaporation. In addition, the effect of surface roughness on the evaporative heat transfer was also investigated. Experimental results showed that the evaporative heat transfer coefficients increased rapidly along with the increase of surface temperature and the heat transfer coefficients increased with the increase of surface roughness.