Plantations of Eucalyptus urophylla×E.grandis in the Dongmen National Forest farm of Guangxi were studied over an eight\|year management period to determine the effects of continuous short\|rotation cropping on the subsequent carbon content in these ecosystems. The carbon sequestration rates and storage, and how carbon is distributed across the ecosystem components were examined for pattern changes as a result of management. The components studied include soil, litter, undergrowth, and tree layers. The results of the research showed: (1)There are differences between the carbon content of the same component in the same layer of short\|rotation Eucalyptus urophylla×E.grandis plantation because of continuous cropping and the stand ages. but no significant differences were found (p>0.05);there are significant differences for the carbon content of different layers and component（p＜0.01）,it shows that the species composition of plantation and its characteristics have great impact on carbon content.(2)The average carbon storage of 7.6a continuous Eucalyptus urophylla × E.grandis short\|rotation cropping plantation is 127.649 t·hm-2, and was 5.03% lower than that of the first generation （134.411 t·hm-2）,no significant difference was found within each layer between the first and second generation（p＞0.05）;Significant differences were found between the different layers in the order of soil layer > tree layer > litter layer > undergrowth layer, (3)Carbon content of two generation increases as the plantation ages increase.(4)Continuous cropping has the potential to influence the patterns of carbon accumulation and storage in Eucalyptus urophylla x E.grandis plantations by increasing the percentage of stored carbon in tree and litter layers, and decreasing the percentage in the undergrowth and soil layers. The main reasons of decreasing carbon in the undergrowth and soil layers are the continuous disturbance of falling trees, mountain smelting and tractor plowing in continuous Eucalyptus urophylla x E.grandis short\|rotation cropping.