Abstract: Based on the LMDI decomposition method and the panel data over the period of 1994 to 2012， this article analyzed the relationship between variation of grain yield and cultivated land use in Hubei and 17 cities with temporal and spatial perspectives， constructed a decomposition model of total grain yield and measured the structure effect， scale effect， strength effect and scope effect. The results showed that planting structure （structure effect） made reduction effects to the variation of grain yield in the dimension of time. Conversely， grain yield per hectare（strength effect） and multiplecropping index（scope effect） made incremental effects to the variation of grain yield. Moreover， cultivated land area（scale effect） made bidirectional driving effects to the variation of grain yield. Overall， the four effects led to grain variation as follows: structure effect> scale effect>strength effect>scope effect. Spatially， the leading factors influencing the variation of grain yield were different. The scale effect area included Huangshi， Jingzhou etc. The scope effect area included Enshi. The structure effect area included Wuhan， Yichang Xiangyang etc. The strength effect area included Xiantao， Shennong etc. On the basis of this， the authors proposed some suggestions including optimizing the planting structure， controling the scale of arable land， accelerating technical progress and carrying out the differentiation management.

Key words: grain production, effects of cultivated land use, temporalspatial analysis, LMDI, Hubei Province