The present study analyzed the improved biochemical properties of the coastal saline-alkali soil in the Yellow River Delta using four factors of a four level orthogonal variance analysis. Four kinds of ameliorants, including cow dung (A), gypsum (B), straw (C), and a water-retaining agent (D), were applied with different formulas. The objective of the present study was to determine the most efficient drainage scheme and provide a theoretical basis for the improvement of the coastal saline-alkali soil in the Yellow River Delta. The results indicated that the effect of cow dung, gypsum, and straw on soil respiration intensity, phosphatase, urease, dehydrogenase, and microbial biomass carbon and nitrogen showed significant(P < 0.05)differences among the treatments with improvement; and the effect of the water-retaining agent on microbial biomass C and N showed significant (P < 0.05)differences among the treatments with improvement. Significantly higher indicator values than the control group were also observed. The contribution of the four kinds of ameliorants differed in the improvement of saline soil conditions. Considering the results, the most efficient formula for soil respiration intensity, enzymes, and microbial biomass C and N was A₄B₃C₂D₂. Compared to the control group, soil respiration intensity, phosphatase, urease, dehydrogenase, and microbial C and N increased by 109.64%, 89.54%, 62.20%, 81.75%, 60.50%, and 118.00%, respectively. The correlation analysis indicated that there were significant (P < 0.05)correlations between the soil biochemical parameters, except for microbial N and urease. The results of the current study could provide a theoretical basis for the improvement and utilization of saline alkali soil in the Yellow River Delta.