Abstract: Using the two-line Japonica hybrid rice Ejingza 1 as the experimental material,effects of different concentrations(10 mg/L,30 mg/L,50 mg/L) of 5Aminolevulinic acid(ALA) applied at initial heading stage on the phosphate uptake and distribution in rice were studied using32P tracer method.The results were as follows: Both the 32P specific radioactivity and32P total radioactivity in panicle,leaf,stem and sheath,root of rice plant treated with 10—50 mg/L ALA were significantly higher than that of the control(0 mg/L ALA).The percentage of32P translocated to the panicles of rice plant treated with 10—50 mg/L ALA was significant higher than that of the control,and was,respectively,(increased) by 4.3%—6.0% during the flowering stage,4.1%—5.0% during the milking stage, and 2.0%—2.7% (during) the dough stage.These results suggested that treatments with 10—50 mg/L ALA increased32P uptake in rice plant and promoted32P translocation to the panicle organ.Correspondingly the plumpness and grain weight of rice plant treated with 10—50 mg/L ALA were considerably different with that of the control.Compared with the control,treatments with 10—50 mg/L ALA increased grain ripening percentage,and grain yield by 4.8%—9.9%,5.4%—14.9% respectively.Treatment with 30 mg/L ALA possessed the highest grain ripening percentage and grain yield.