Abstract: In this paper,studies were made of the effect of different soil pH treatment on the growth of M.dawsoniana seedlings.With pH value of 7.5 as the control,the treatments were conducted by using different pH values of 4.5,5.5,6.5,8.5 and 9.5,respectively.The experimental results displayed the damage and growth parameters of seedlings under different soil pH treatments.When pH value was between 5.5 to 7.5,the morphological characteristics,plant height growth,basal diameter and leaf area of the seedlings were remarkably higher than other treatments.Among them,all indicators of seedlings reached the maximum when pH value was 6.5.Besides,when pH value was lower or higher than 5.5,the growth of seedlings was significantly inhibited.