Abstract: In order to explore the changes of soil microbial functional diversity in saline alkali land with vegetation succession,Biolog Eco microplate method was used to study the natural succession sequence and the functional diversity of soil microbial community of different vegetation after artificial restoration in Songnen Plain saline-alkali land. The results showed that the carbon source metabolism of soil microorganisms increased significantly（P＜0. 05）, the Average Well Color Development（AWCD） increased from 0. 04 to 0. 61 at 96 h, Shannon diversity index（H） increased from 1. 43 to 3. 20, Simpson dominance index（D） increased from 0. 70 to 0.96, and McIntosh index（U） increased from 0. 75 to 4. 03 with the succession of vegetation from alkali spot to leymus chinensis. After artificial restoration, the amount of carbon source used by soil microorganisms in herbaceous and shrub-grass communities was the largest, while the amount of carbon source used by soil microorganisms in artificial forest communities decreased. Soil microbial AWCD,Shannon diversity and richness index, Simpson dominance index and McIntosh index were significantly positively correlated with soil organic matter and total nitrogen content（P＜0. 01）, and significantly negatively correlated with soil density, pH and total salt content（P＜0. 01）.