In this experiment, soil mixed with sand and composted straw (SSJ) and soil mixed with sand andbiochar (SSS) were used as the replacement media for urban green space to explore their changes in physical and chemical properties after adding PAM with concentration of 0~1.5%.The suitable dosage of PAM was expected to be found to provide theoretical and technical support for soil refilling in urban green space. The results showed that adding PAM could reduce the bulk density of the media, and increase the saturated hydraulic conductivity and saturated water content. The change trend of bulk density and saturated hydraulic conductivity with the increasing of PAM could be described by a quadratic curve. However, when the PAM dosage was 1.5%, the saturated hydraulic conductivity showed a tendency to decrease compared with the PAM dosage of 1.0%. Whereas the bulk density showed an upward trend. The application of PAM could reduce COD desorption quantity of the media.With the increasing of PAM dosage, the nitrogen and phosphorus desorption of SSJ media showed an increase trend, while the nitrogen and phosphorus desorption of SSS media decreased first and then increased. On the whole, the SSS media was superior to the SSJ media when the PAM concentration was 0~1.5%. When the dosage of PAM was 1.0%, it could improve the water retention and water conductivity capacity of media to the greatest extent, and reduce COD desorption.