Abstract: High content toxic gas easily occurs in the unloading operation process for South Pars condensate. This paper analyzes the basic properties of condensate and distribution situation of sulfides, and identifies the composition of toxic gas. It describes the matters needed to be attended for initial unloading and unloading operation in terminal in details. Before unloading operation, risk identification for all operation links should be carried out, emergency response scheme and the integrity of equipments are necessary. Before unloading operation, operation preparation shall be carried out first, and an operation alert area must be set up to provide an unblocked fire passage. When unloading operation begins, monitoring for hydrogen sulfide should be kept, and after the unloading operation, timely replacement of the pipeline should be done. It is pointed out that the inspection port and unloading hatch are possible leakage areas. It is suggested that inspecting hydrogen sulfide and mercaptan should be made for other products oil. Special measures for malodor prevention in terminal area are given.