Polysaccharide was extracted from seeds of Citrus Grandis in Jiangyong using ultrasonic-assisted surfactant extraction. Based on the results of single-factor designs, three important factors including extraction temperature, extraction time and solid/liquid ratio were considered in the extraction process by the response Surface Method (RSM) with the Box-Behnken Design method. The results showed that the optimum extraction condition was as follows: ultrasound pretreated time of 4 min, extracting time of 50 min, extracting temperature of 71 ℃, SLS addition of 1.5%, and a ratio of solid/liquid of 1∶20 g/mL. The extraction yield of the polysaccharide could reach 4.69%.