Under aerobic conditions imazosulfuron is moderately fast degraded in soil with a half-life between 20 and 80 days. Imazosulfuron is mineralized to a low extent. The two metabolites IPSN and HMS were considered as major products of imazosulfuron, which both had an AR value over 10%. The degradation of HMS to IPSN is fast with a half-life of HSM between 8 to 15 days. Furthermore, IPSN is degraded rather slow with a half-life between 80 to 100 days. The two minor compounds ADPM and UDPM were fast to moderately degraded with half-lives of around 5 days and 45 days, respectively. 14C-imazusulfuron degraded in all aerobic soils by several mechanisms including microbial degradation. The transformation products are further degraded to non-extractable residues.