Abstract: Stable carbon isotope analysis is a rapid and reliable technique developed in recent years and may reveal many processes of carbon dynamics in plants. As a result of isotope effect, discrimination against 13C occurs during carbon cycle. Plants discriminate against 13C during photosynthesis in ways, which reflect plant metabolism and its environment. 13C/12C ratios is a genetic controlled characteristic and at the same time affected by environmental factors, thus it has stored all kinds of environmental information which is theoretical basis for reconstructing past climate and predicting that of future using stable carbon isotope composition. This paper reviewed the effect of environmental factors such as light, temperature, CO2, water, nutrient, salinity, air pollutants on stable carbon isotope composition in plants.