LCA is the embodiment and technicalization of sustainable development, is tolerance and technical support of sustainable development. Meanwhile, LCA is the important mean and scientific method of ecological environment design, clean production audit, environmental material development too. Firstly, this thesis expatiates on the proposition background and basic intension of LCA. Secondly, the thesis summarizes domestic and foreign research actuality of LCA on this basis. Foreign LCA theoretical research has achieved great success, but still there are places not perfect either, which reflect in technological detail mainly. Because of short developing time, domestic accumulation of LCI is still far from enough. Finally, the thesis summarizes: LCA is not only applied to technological sciences and natural science, but also is applied extensively to social science, economic science, management science and international relationship etc; The implementation of LCA not only depends on LCA standard, but also depends on the implementer's exact understanding of method and target and one's own experience and technological background, and there is much limitation mainly in practical application.