Abstract:Seeds and one-year seedlings of Casuarina equisetifolia from 20 provenances were studied on weight per thousand seeds and seven characters (height,ground diameter,thickness of first order branches,length of first order branches,length of second order branches,nodes per branch,teeth),in order to investigate the morphology diversity of C.equisetifolia and collect the base genetic information for early genetic selection of this specie.The results showed that:(1)highly significant variance of weight per thousand seeds could be both found between the provenances and the regions(P<0.01),and the variation of weight per thousand seeds has shown significant geographic pattern.The weight per thousand seeds would decreased with the increment of longitude;(2)height and ground diameter have extremely significant different between regions and in region(P<0.01),the provenance from Do Donggang Thailand has the best growth condition,for height is 76.6 cm,ground diameter is 4.64 mm;while provenance from Tonga has the worst seedling growth,for height is 28.3 cm,ground diameter is 2.58 mm;(3)highly significant difference of thickness of first order branches,length of first order branches,length of second order branches,nodes per branch and teeth could be found between regions and in region;of which,the coefficient variation between regions of teeth was maximum (82.15%);(4)path analysis results showed that length of first order branches has a significant effect on height,thickness of first order branches and length of second order branches have significant effect on ground diameter.These three traits could be used as reference factor for excellent variety selection of C.equisetifolia.