Abstract: A field experiment was conducted to study the effects of foliar spraying of three kinds of compound agents \[plant polysaccharides (P₁), plant polysaccharides plus 5-aminolevulinic acid (P₂), and plant polysaccharides plus 5-aminolevulinic acid and dimethylpiperidinium chloride (P₃)\] at the initial flowering stage of winter wheat on its yield components, sucrose content, soluble sugar content, the accumulation and translocation of dry matter, nitrogen and phosphorus. The grain number per spike and kilograins mass of winter wheat increased with the spray of the compound agents. The grain yield increased by more than 8.5% compared with the control. Within 20 days after spraying the three compound agents, the sucrose content of flag leaf had an obvious increase. Compared with the control, P₁ and P₃ increased the soluble sugar content by more than 4.5% and 11.0%, respectively. P₃ enhanced the accumulations of postanthesis dry matter, nitrogen and phosphorus by 48.5%, 116.9% and 18.1%, respectively. Correspondingly, contributions of accumulated postanthesis dry matter and nutrient to grain yield increased significantly. Whereas, the contribution of translocated preanthesis nutrient to grain yield in P₃ treatment was smaller than in the other treatments. The high yield of winter wheat was related to the regulation of photosynthetic product supply in vegetative organ, the increased soluble sugar content in grain, and the accumulation of postanthesis dry matter and nutrient regulated by the plant polysaccharidescontaining compound agent.