Abstract: Taking Betula alnoides seedlings as experimental material,the single factor randomized complete block design was used to carry out the light substrate and soil mixed seedling raising tests on 4 kinds of light mediums mixed with soil,the pure soil was used for the control,and variance analysis and comprehensive evaluation method on the growth index were adopted to evaluate the effect of the seedling raising substrates.The results showed that the growth difference between 5 kinds of different substrates on Betula alnoides seedlings is significant,and the seedling height,diameter,root length,root number,leaf fresh weight,root fresh weight,whole plant fresh weight,root shoot ratio of substrate 2 exhibited the maximum,its comprehensive score was also the highest,reaching 3.9196.Therefore,the substrate 2 (broadleaf sawdust + chicken manure):(forest soil)=2:1 should be the optimum substrate for the growth of Betula alnoides seedlings.