Abstract: The synthesis conditions for synthesizing light-color rosin-pentaerythritol resin were examined using first-grade rosin and pentaerythritol as starting materials and eight kinds of catalysts. The relationships among type of catalyst, complexization condition and quality of product were investigated. In addition, the influences of reaction temperature, reaction time, dosage of materials and other factors on the qualitative indexes of products were examined. The suitable synthesis conditions for No.145 rosin-pentaerythritol resin were obtained as follows: reaction temperature (275±2)℃,reaction time 6 h, ratio of rosin, pentaerythritol, catalyst A and catalyst G 1:0.12: 0.002:0.000 5. Quantitative indexes of the product obtained under aforesaid conditions were: color 3 (Gardner), softening point 91.7℃, acid value 24.8 mg/g.