Global climate change has been one of the most concerned environmental problems in the world since the 1980s. Since stable carbon composition ( delta~(13)C) in plant tissues can record abundant information on climate changes,it has been widely used as an important climate proxy in global change studies and becomes a powerful tool for obtaining paleoclimate information,understanding paleoenvironment reconstruction and modern climate change,and predicting future climate trends. However,a lot of potential uncertainties have always involved in the reconstruction of paleoclimate and paleoenvironment by carbon isotope of the past period sediment or fossils. Among them,the most dominant uncertainty is due to our poor understanding of the relations between carbon isotope ratios of plants and climatic factors and the climatic and environmental significance indicated by modern plant delta~(13)C. This may limit the application of plant delta~(13)C in the study of climatic and environmental changes. Based on the Summary of plant delta~(13)C fractionation and carbon isotope distribution of different photosynthetic plants,the effects of environmental factors,e. g. ,temperature,precipitation,atmospheric CO_2 concentration,and altitude on terrestrial plant delta~(13)C and their relationships were reviewed in this paper,and the response mechanism of plant delta~(13)C to climate changes were also analyzed. Furthermore,the current existing problems and the future prospects in carbon isotope study were discussed. It is pointed out that strengthening some studies such as the response of C_4 plants delta~(13)C to climate environmental parameters,the transformation relation of different scale plant delta~(13) C,intersection and permeation of related disciplines,and various proxies and scientific method,will undoubtedly make us have a more accurate understanding of the climate history and eventually broaden the development of the field during the process of global change study by plant carbon isotope techniques.