Abstract: Field plot experiment was carried out to study the effect of phosphorus application on soil phosphorus adsorptiondesorption characteristics under three cropping patterns including maize/soybean relay intercropping (M/S), maize monoculture (M), and soybean monoculture (S). Results showed that without phosphorus fertilization, the system crop yield under M/S was increased by 9.8% and 79.1% compared with that of M and S, respectively, and the land equivalent ratio (LER)  was 1.58. With phosphate fertilizer application, the system crop yield under M/S was increased by 10.4% and 80.3% compared with that of M and S, respectively, and the  LER was 1.62. The system crop yields under M/S, M and S with phosphate fertilizer application were increased by 12.7%, 12.2% and 17.6%, respectively, compared with that without phosphorus fertilization. Among three cropping patterns, the soil buffer capacity (SBC) values were in the order of M/S>M>S regardless of phosphate fertilizer applied or not. The SBC values of M/S, M and S without phosphate fertilizer application were reduced by 19.6%, 30.3% and 12.0% compared with phosphate fertilizer application treatments, respectively. The soil desorption per absorption (b) values of the three cropping patterns with phosphate fertilizer application were in the order of M/S>M>S, and the  b values increased by 10.9%, 39.1% and -9.6%, respectively, compared with non phosphate fertilizer application. The soil phosphorus maximum absorption (Q_m) and soil phosphorus desorption rate also showed the same trend.