Abstract：The propagation from meteorological drought to agricultural drought is a key process through which precipitation deficit translates into soil moisture deficit, which largely determines the actual severity of drought impacts and further affects crop yield and agricultural economic benefits. Using the Standardized Precipitation Index (SPI) and Standardized Soil Moisture Index (SSI), drought propagation and its driving factors in Jiangsu Province since 1990 were systematically investigated by integrating run theory, the maximum Pearson correlation coefficient method, copula functions, and the geographical detector. Agricultural drought events occurred less frequently than meteorological drought events but had longer mean durations and greater mean intensities. Propagation times were concentrated between 3 and 5 months. Spatially, a 3-month propagation time predominated, with faster propagation in southern Jiangsu and slower propagation in northern Jiangsu. The probability of agricultural drought increased with meteorological drought severity. Under mild, moderate, severe, and extreme meteorological drought, the mean probabilities of agricultural drought occurrence were 0.51, 0.65, 0.75, and 0.83, respectively. Propagation thresholds differed markedly among agricultural drought severity levels, with more severe agricultural drought requiring a greater meteorological water deficit to be triggered. Precipitation was the dominant factor controlling spatial variation in propagation time, while soil moisture and mean air temperature also made important contributions. Interactions among all pairs of factors enhanced their explanatory power for spatial differences in propagation time, and the interaction between precipitation and soil moisture was the strongest. These findings provide a scientific basis for regional agricultural drought monitoring, early warning, and water resources management, and offer theoretical support for reducing the adverse impacts of drought on agricultural production.