Abstract: This paper deals with the effects of soil preparation to forest tree growth and economic benefit using the data of four kinds of soil preparation experiment(soil preparation of heigh norm(liao hao),strip,overall and spot)for Cunninghamia lanceolata and using the method of dynamic economic evaluation.A soil preparation experiment for C. lanceolata plantation was established on yellow-red soil in Guizhou Province in 1978. The results of 17 years research showed that type of soil preparation affected survival rate,tree growth and economic benefit, the effect of soil preparation on stand growth lasted in a certain period of time. The effects to various current annual increment vanished in the 7th～10th year,the effects to stand mean height,mean DBH and single-tree volume occured before 10～12 year,and the biggest difference occurred in the 7th～10th year.The effect of soil preparation to DBH was 1～2 year less than to tree height and single-tree volume.The growth of heigh norm(liao hao)soil preparation was the best,but the results of fund utilization was not satisfactory and the profit ratio was 2.37% lower than that of spot soil preparation, the profit of each unit investment making was 19.03% lower than that of spot soil preparation,thus the economic results of heigh norm soil preparation was not satisfactory.By synthesis analysis the results of growth and economic benefit of various soil preparation,the best type manner of soil preparation was spot soil preparation,with the specification of 30 cm×30 cm×30 cm or 40 cm×40 cm×30 cm.