Microspheres of biodegradable polymers have been widely investigated in delivery system for bioactive compounds. In this study, microspheres were prepared from polyblend of poly(lactic acid) and polycaprolactone using water-in-oil (w/o) emulsion solvent evaporation method with Nonidet SF-5 as surfactant. The effect of Nonidet SF-5 on the size of microsphere and its distribution was studied by varying the volume of surfactant (1, 1.5, and 2) mL. Additional variations such as emulsion stirring speed (700, 800, and 900) rpm and dispersion stirring time (0.5, 1, 1.5, and 2) h were also conducted. Microspheres were characterized using Particle Size Analyzer (PSA), Fourier Transform Infrared (FTIR), and optical microscope. The results showed that the addition of surfactant volume decreased the microspheres size from 34.58 μm to 28.70 μm and the most uniform microspheres size was obtained at 1 mL of Nonidet SF-5. While the microspheres that produced through variation of emulsion stirring speed showed the same size, that was 31.50 μm and the most uniform microspheres size was obtained at 800 rpm. Moreover, the increasing in dispersion stirring time also decrease the microspheres size from 31.50 μm to 19.76 μm, but it did not affect the microspheres size distribution.