Based on 25 years (1981 - 2005) of continuous positioning observation data on desert shrub in Xilingaole area of Alashan league in Inner Mongolia, by M - K trend method and correlation method, the growing periods and yield trends of the 5 main species of desert shrubs, soil moisture trends, and the relationship between them were analyzed. The results showed that the soil moisture, especially that of 10 -20cm soil layer decreased obviously (P <0.05). Compared with 10 -30cm, the soil moisture of 30 -50cm soil layer was relatively stable. During 1981 -2005, the reviving date, flowering and withering date of the 5 species of desert shrubs all had a ahead trend, especially for withering, reviving on the second, which made the growing length of the 5 desert shrubs reduced. The fresh weight of the 5 species of desert shrubs was significantly decreased. Compared with dry weight, fresh weight decreased more obvious. Soil water content mainly affected the reviving date of the 5 desert shrubs. The higher sail water content was, the earlier reviving date. The 30 - 50cm soil layer was the main layer affecting shrubs reviving due to its relatively stable. The 10 - 20cm soil layer had a significant impact on dry weight and fresh weight of desert shrubs. The correlation of dry weight, fresh weight and average soil moisture of last year was significant than that of the current year, indicating that dry weight and fresh weight of desert shrubs more closely related to pre-soil moisture.%基于孪井滩牧业气象试验站25a( 1981 - 2005年)连续定位观测资料,对阿拉善主要荒漠天然灌木的生育期与产量变化趋势、土壤水分变化趋势及其对灌木的影响进行分析.结果表明,浅层与深层土壤含水率均呈下降趋势,其中10 -20cm浅层下降趋势更为明显(P＜0.05)；5种荒漠灌木的返青期、开花期以及黄祜期均有提前趋势,其中黄枯期提前尤为明显,返青期次之；5种荒漠灌木的干重和鲜重也均有明显下降趋势,与干重相比,鲜重下降更为明显.相关分析结果表明,土壤含水率与灌木生育期以及干鲜重的相关性因不同时段和不同灌木品种而异,土壤水分主要影响返青期,土壤含水率越大,返青期越早.30 -50cm土层土壤含水率的变化相对较稳定,成为影响灌木返青期的主要土层；开花期和黄枯期对水分变化没有显著反应；10 -20cm浅土层土壤水分对荒漠灌木的干鲜重影响最为显著；荒漠灌木干鲜重与上一年不同土层土壤含水率的相关性明显好于当年.无论是深层还是浅层土壤含水率,与干重的相关性均比鲜重小.
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