Resveratrol-loaded poly($varepsilon$-caprolactone) (PCL) nanoparticles were prepared by oil in water (O/W) emulsion solvent evaporation method. The morphology of the nanoparticles was evaluated using atomic force microscope (AFM), in which well-shaped and rigid nanoparticles were prepared. The mean particle size of nanoparticles prepared using only dichloromethane (DCM) ($523.5{pm}36.7;nm$) was larger than that prepared with a mixture of DCM and either ethanol (EtOH) ($494.5{pm}29.2;nm$) or acetone ($493.5{pm}6.9;nm$). The encapsulation efficiency of nanoparticles prepared only with DCM as dispersed phase ($78.3{pm}7.7%$) was the highest of those prepared with solvent mixtures. An increase in the molecular weight of PCL led to an increase in encapsulation efficiency (from $78.3{pm}7.7$ to $91.4{pm}3.2%$). Pluronic F-127 produced the smallest mean size ($523.5{pm}36.7;nm$) with the narrowest particle size distribution. These results show that dispersed phase, molecular weight of wall materials, emulsion stabilizer could be important factors to affect the properties of nanoparticles.