Soil CO₂ efflux, which represents the CO₂ efflux from the soil surface, is an important process of ecosystem carbon cycle. Soil CO₂ efflux is mainly controlled by soil temperature and soil water content. Response of soil CO₂ efflux to rainfall via rapid change in soil water content and soil temperature are not well understood due to instrument limitation and difficulty in measurement during rainfall. This study was designed to (1) examine the mechanisms of soil respiration following rainfall under different site conditions during the growing season and (2) to develop and evaluate empirical models predicting changes in soil CO₂ efflux using soil temperature and soil water content. The experiments were conducted in wheat and peanut fields at the University of Georgia’s Southwest Georgia Research and Education Center in Plains, GA. Soil CO₂ efflux was continuously monitored by soil gradient method (GMP343, Vaisala) in control plot that measured total soil CO₂ efflux and in trenched plot that only measured microbial respiration and automated soil chamber method (Li-8100, Licor) during the 2007 growing season. We found that soil CO₂ efflux responds differently to variations in soil temperature and soil water content and significantly increases  in both plots following rainfall. The dynamic pattern of soil CO₂ efflux in response to rainfall was well described by Y = Y₀ + a(t/τ)²exp(-t/τ), where Y is soil CO₂ efflux, t is day after rainfall, Y₀, a and τ are coefficients, respectively. Soil CO₂ efflux is strongly correlated with soil temperature and increased with the increasing the soil temperature. Moreover, soil water content had both positive and negative impacts on the soil CO₂ efflux and was best described by a quadratic function. We also conducted a multivariate analysis with independent variables of soil temperature and soil water content to predict soil CO₂ efflux. Daily soil CO₂ effluxes calculated by the model were consistent with the field measurements. Our results suggested that the enhancement of soil CO₂ efflux after rainfall was positively correlated with the amount of rainfall, soil CO₂ efflux before rainfall and soil water content.