Abstract: 1. From a comparison of the growth rate of Chinese Cryptomeria fortunei Hooibrenk ex Otto et Dietr.and that of Japanese sugi(C.japonica(L.f.) D.Don),including both seedlings and mature trees grown in different geographical localities,it has been shown that the former is better adapted to the warm and humid southern region,while the latter is hardier in the cold winter of the northern region.By such comparison,it is evident,each species has its own genetic merits which might be taken as an indication of rich germaplasm source for improvement of these trees. 2. Test of Chinese sugi seeds from 21 geographical localities showed marked differences in seed weight and germination percentage.They are colsely correlated,with γ= 0.6234. 3. In provenance test of these seeds at 4 stations,the first year seedlings showed statisically significant differences in growth rate.The best one is about twice that of the poorest one.The percentages of increase in growth from seeds of different provenances as compared with those collected at the 4 local stations,are 18—72%.