[Objective] To determine the utilization of phosphorus in slope ecological rehabilitation substrate in order to provide theoretical basis for optimizing substrate formulation.[Methods] Adsorption-desorption characteristics of phosphorus in five types of slope ecological rehabilitation substrates were studied via constant temperature shaking culture. Then, the adsorption-desorption capacity and loss risk of the five substrates were compared with factor analysis.[Results] The maximum adsorption capacity(Q_m), maximum buffering capacity(MBC) and phosphorus sorption index(PSI) have shown that the phosphorus fixation capacity of the five substrates was in an order of the natural secondary forest > the external-soil spray seeding > the thick layer substrate > the framed beams soil covering > the vegetation-compatible concrete. It showed that Q_m had positive correlation with clay content, while it had negative correlation with organic matter content and pH value. The desorption ability of the five types of substrates was the vegetation-compatible concrete > the framed beams soil covering > thick layer substrate > the external-soil spray seeding > the natural secondary forest. The average desorption rate had significantly positive correlation, and it also had positive correlation with organic matter content. The negative correlation was found between the average desorption rate and clay content. This study showed that Q_m, MBC, PSI, the average desorption rate and easy desorption phosphorus(RDP) could best reflect the phosphorus loss risk of five different substrates. It showed that from high to low, the order of the phosphorus loss risk was the vegetation-compatible concrete, the framed beams soil covering, the external-soil spray seeding, thick layer substrate and the natural secondary forest.[Conclusion] The natural secondary forest has the highest conservation capacity of phosphorus in the five ecological rehabilitation engineering ways, while the vegetation-compatible concrete has the lowest. In slope ecological rehabilitation engineering, the proportion of clay content should be increased and the dosage of cement should be decreased, or buffering material be added into substrate, so that the substrate can have a stronger phosphorus adsorption capacity, the larger phosphorus storage, the smaller phosphorus loss risk. Thus, the utilization ratio of phosphorus can be improved and the supplying ability can last longer.