Different loads of municipal solid waste compost (MSWC) were applied to hyper saline salt lake soil under laboratory conditions to monitor biological soil quality Microbial biomass-C (MBC), catalase, dehydrogenase, urease, alkaline phosphatase arylsulfatase, and beta-glycosidase activities were analyzed following 14, 30, and 50 days of incubation In general, MBC and the oxidoreductase and hydrolase enzyme activities were significantly enhanced by addition of MSWC at 20 and 40 t ha (1) doses, but they decreased at 120 t ha (1) Overall, the results show that the addition of MSWC to hyper saline soils can improve soil biological quality, in spite of its high salt content, which is an important step in any attempt to use them as biosaline agricultural soils However, substances such as heavy metals in MSWC could limit the use of compost for this purpose, consequently analysis of MSWC is recommended prior to its use