Abstract: The impact of Chinese fir Cunninghamia lanceolata (Lamb.)Hook provenances planted in the same region on their site index curves was tested by the method of random effects test with the data from eight forest farms, Jigongshan, Hongya, Dagangshan, Liuzhou, Liufengshan, Gongxianluobiao, Gongxianminsheng and Qionglai.Results showed that slope parameters of site index curves among Chinese fir provenances planted in the same region are not significantly different while site indices are, and that there is significant difference in the slope parameters among planting regions.