In order to understand the effects of fertilization with biogas slurry of different concentrations on the growth quality of cucumber seedlings and soil chemical properties,the growth morphological indexes,physiological indexes and soil chemical indexes of cucumber seedlings treated with biogas slurry of different concentrations were measured.The results showed that biogas slurry fertilization significantly increased the plant height,stem diameter and root length of seedlings,and the strong seedling index of 40% biogas slurry was 21.5% higher than that of CK.Different biogas slurry fertilization significantly increased the total chlorophyll,P_n,C_i,G_s and T_r of cucumber seedlings.The chlorophyll content of 80% biogas slurry was the highest,Gsand T_r of seedlings with 60% biogas slurry changed significantly.Compared with CK,application of biogas slurry significantly increased soluble protein,soluble sugar and root activity.Fertilization with biogas slurry significantly increased pH,organic matter mass fraction and rapid available phosphorus content of cucumber growing soil,and promoted soil organic matter content to increase by 3.77%（P＜0.05）,therefore,fertilization with biogas slurry can significantly improve the quality of cucumber seedlings and the basic chemical properties of cucumber root soil.