In stereolithography, the most important procedure for improving the accuracy of modeling is to clearly identify the relationship between the method of laser irradiation and the solidification of photocuring resin. Thus, a theoretical analysis is made to find any effect on the solidification, namely the thickness and width of solidified resin influenced by laser power, laser beam diameters, laser scanning speeds, and properties of photocuring resin. These analytical results are compared with respective test results. The results can be summarized by the following. 1. The cured thickness of solidified resin can be represented by a function of the energy density at the center of laser, the attenuation coefficient, and the critical curing energy density of photocuring resin. 2. The cured width of solidified resin can be represented by a function of laser beam diameters, the energy density at the center of laser, and the critical curing energy density of photocuring resin. 3. Photocured models, which have been manufactured by controlling energy density at the center of laser, would have high manufacturing accuracy, and therefore can be applied as industrial design models.