The analysis of foliar spraying dosage for seedling growth,in Shandong province forest test,according to the dose of BGB microbial agent into four treatments,CK(no treatment)A1(10g/strain)A2(30g/strain)A3(50g/strain),observe the effect of different amounts of microbial preparation on seedling growth and soil nutrients.The results confirmed that different doses of microbi-al agents affected the growth of Pinus tabulaeformis seedlings.The seedling height,ground diameter and crown amplitude of each treat-ment were ranked by A3>A2>A1>CK(P<0.05).Overall,A3 treated seedlings showed the best growth;the survival rate of seed-lings of different doses of microbial preparations was higher than that of CK group.With the increase of microbial dose,the survival rate gradually increased with a positive correlation.The comparison of net photosynthetic rate,stomatal conductance and transpiration rate was A3>A2>A>A1>CK.Overall,A3 showed obvious advantages;organic matter,alkali nitrogen,and quick phosphorus were all higher than other treatments(P<0.05),A3 was significantly higher than CK group(P<0.01),significantly higher than A1 and A2(P<0.05),showing the trend of A3>A2 A 1>CK.This shows that the foliar spraying of microbial preparation also promotes the growth of Pinus tabulaeformis seedlings and improves the soil nutrients,with the best dose of 50g/plant.