Abstract: Based on the data collected from a long-term experiment of Cinnamon Soil for 26 sites, changes of soil fertility index and crop yield of Cinnamon Soil and its affecting factors had been analyzed. The results showed that the content of soil organic matter was increased from the beginning value 11.50 g/kg of 1986 to 15.75g/kg of 2006; the content of total N of soil was increased from the beginning value 0.73 g/kg of 1986 to 1.07 g/kg of 2006.The content of soil of available N was increased from 73.5 mg/kg in 1986 to 94.6 mg/kg in 2006; the content of soil available P was increased from 18.1 mg/kg of 1986 to 28.7 mg/kg of 2006. The content of soil available K was increased with the time. In a word, the indexes of soil fertility of Cinnamon Soil presented a growing trend. The increase of organic matter, total N, available N and P was sharper than available K; soil pH kept stable; meanwhile the yields of wheat and maize also appeared on upward trends.