The grain production in Hunan province has reduced since 1999 and it reached the lowest in 2003. Grain production in 1999 and 2003 were selected as representative years to investigate major limiting factors at provincial, municipal and county scale. The results showed that on the provincial scale both the growing area and grain yield were reduced and 80. 53% of the grain reduction was caused by the decrease of the growing area. On the municipal scales,grain production in all cities reduced except Chengzhou in Hunan province and 83.55% of grain reduction was caused by the decrease of the growin...