[Objective] To provide a technical approach and theoretical basis by finding the optimal organic fertilizer application amount and the optimal water retaining agent ratio for the improvement of brown soil tillage, the study investigated the effect of organic fertilizer with water retaining agent on the hydraulic properties of brown soil tillage . [Methods]A split-plot experimental design was conducted, using the topsoil of the brown soil in Shanxi Province. The main plot treatments were based on organic fertilizer application amount: F1 (0 t/hm2), F2 (45 t/hm2), F3 (60 t/hm2) and F4 (75 t/hm2). The sub-plot treatments included four water-retaining agent application amount: B1（0 kg/hm2）、B2（300 kg/hm2）、B3（600 kg/hm2）and B4（900 kg/hm2). The effects of the application amount of organic fertilizer and water retaining agent on soil water characteristic curve, specific water capacity and available water content were studied. [Results]① Soil water holding capacity and water supply capacity were enhanced in the organic fertilizer combined with water retaining agent treatment compared to water retaining agent alone. Besides, effective water content was increased. ②The improvement effect of organic fertilizer combined with water retaining agent on soil hydraulic properties varied with different application amount of organic fertilizer. The water-holding capacity at low water suction of the test soil was F3>F2>F4>F1, the water-supplying capacity was F3>F2>F4>F1, and the content of effective water was F3>F2>F4>F1. ③ Under the treatment of F3, the water holding capacity and water supply capacity of the soil showed a tendency of increasing and then decreasing with the increase of the proportion of water retaining agent. There was a parabolic relation- ship between soil effective water content and water retaining agent application ratio, and the relation equation was Y=12.87+1.74X-0.95X2 (R2=0.9493). [Conclusion]The improvement effect is the best under the treatment of medium amount of organic fertilizer(60 t/hm2) combined with water retaining agent, and the optimum proportion of water retaining agent under this amount of organic fertilizer is 0.91%.