Abstract: The introduced Eucalyptus dunnii growing in northern high latitude areas of Jianyang in Fujian was taken as the research object while Cunninghamia lanceolata and Pinus massoniana used as comparison. A discussion was made for the effects on the tree plantation introduced in high altitude area based on the analysis of class structure, height structure, species composition. The result showed: comparing with other forest stand, the average DBH of 9yearold Eucalyptus dunnii was 12.1cm, and the average of height was 119cm. It is clear to see the growth of the species was faster than Cunninghamia lanceolate and Pinus massoniana. The species composition was 19 and higher than Cunninghamia lanceolate(11) and Pinus massoniana(10). In Eucalyptus dunnii pure forest, the important value of Eucalyptus dunnii was 68547%. Meanwhile, in shrubs and herb layer Pleioblastus amarus and Dicranopteris pedata had greater important value than others.