Stomatal conductance is a key indicator of the balance and cycles of heat, H₂O, and CO₂ fluxes at the vegetation-atmosphere interface. Thus, it is essential to study the heat and H₂O transfer in the soil, vegetation, and atmosphere andevaluate the status and role of vegetation, by considering the relationships between stomatal conductance and environmental factors, and by modeling and extrapolating the cumulative effect of stomatal conductance at the leaf, canopy, and regional levels. This paper summarized three aspects of research in this area: (1) the relationships between stomatal conductance and environmental factors at the leaf and canopy levels, (2) the simulation of stomatal conductance, and (3) the up-scalingof stomatal conductance from the leaf to canopy level and from the canopy to regional level. The results showed that the relationships between stomatal conductance and environmental factors were not consistent, because hereditary characteristics, environmental conditions, and time-scales varied; in addition, the comprehensive effects of environmental factors were not considered. A hypothesis was made concerning the mechanism underlying the relationship between the environmental factors and stomatal conductance. Systematic control and simultaneous observation should receive more attention when studying these combined influences. At present, Jarvis and BWB are the most commonly used stomatal conductance models. The suitability of these two models differed among research goals, study sites, and environmental conditions, so model selection should be carried out on a case-by-case basis. This paper also summarized other models. The results of up-scaling stomatal conductance from the leaf to canopy level and from canopy to the regional level showed that while research on the former is well established, the latter is still difficult to validate. Finally, we recommend that future research should focus on the following: (1) choosing the best model to simulate stomatal conductance, based on the environmental conditions; (2) considering interactions between environmental factors, and take into consideration their combined influence on stomatal conductance; (3) studying the coupling between the BWB and photosynthetic models; and (4) improving simulation accuracy at large scales.