Global climate change has a significant impact on carbohydrate allocation in plantation ecosystem,which results in the serious death of plantations and changes from carbon sink into carbon source. In order to alleviate global climate change influence on plantations,the scientific forest management should be taken to increase photosynthetic efficiency,decrease atmospheric CO_2 concentration,promote carbon storage and improve forest adaptation. The area of coniferous plantations in China accounts for above 70% of the total area of the plantations,and the average carbon storage per hectare in China was only 17% of the world's average in 2009. Thus,how to rapidly increase carbon storage should be placed on improving the existing coniferous plantations. However,there is highly controversy about the mechanism of conifer carbohydrate distribution and how conifers adapt to environmental changes through adjusting carbon allocation patterns. This review introduces definition and judge rules of carbon source and carbon sink at the different spatio-temporal scales. Secondly,this paper discusses carbohydrate transport pathway and allocation patterns with growth,storage and defense. Thirdly,this paper analyzes external environment factors and intrinsic regulative mechanism of carbohydrate allocations. Finally,the future research focus is proposed,alongside the carbohydrate allocation core theory and the silviculture measures in improving the carbon sequestration capacity of coniferous forests. The intrinsic carbohydrate allocation regulative mechanism should focus on the different spatio-temporal scales. Attention should be paid to the mechanism of carbohydrate distribution in coniferous trees under extreme climate conditions. The corresponding carbon forest silviculture theory system should be established.