The photolysis of simulating low concentration of hydrogen sulfide malodorous gas was studied under UV irradiation emitted by self-made microwave discharge electrodeless lamps (i.e. microwave UV electrodeless mercury lamp (185/253.7nm) and iodine lamp (178.3/180.1/183/184.4/187.6/206.2nm)). Experiments results showed that the removal efficiency (ηH2S) of hydrogen sulfide was decreased with increasing initial H 2 S concentration and increased slightly with gas residence time; H 2 S removal efficiency was decreased dramatically with enlarged pipe diameter. Under the experimental conditions with pipe diameter of 36mm, gas flow rate of 0.42standardls −1 , ηH2S was 52% with initial H 2 S concentration of 19.5mgm −3 by microwave mercury lamp, the absolute removal amount (ARA) was 4.30μgs −1 , and energy yield (EY) was 77.3mgkWh −1 ; ηH2S was 56% with initial H 2 S concentration of 18.9mgm −3 by microwave iodine lamp, the ARA was 4.48μgs −1 , and the EY was 80.5mg kWh −1 . The main photolysis product was confirmed to be SO42- with IC.