The synthesis of tributyl citrate catalyzed by cation exchange resin modified by SnCl4 was investigated.As shown in the results of Fourier transform infrared spectrum and X-Ray fluorescence spectrum, the skeleton structure has not changed and loading factor of Sn4+ is 13.47% after modified by SnCl4. The optimization of reaction parameters was performed ,showing that maximum yield of tributyl citrate of 97.3% could be obtained under the conditions that temperature was 155 ℃,duration was 6 h,molar ratio of n-butanol to citric acid was 4.1:1 and catalyst amounts was 4.5%(based on the total mass of reactants).The catalyst could be reused 8 times without any disposal and the yield still reached 96%.