Abstract: Using the plate assay method with Tween 80 as substrate of lipase,122 soil samples collected from Hebei province were screened and a bacterial strain Lipa1318 with high lipase activity was obtained. The results of morphological features,the physiological and biochemical characteristics and 16 S r DNA sequence alignment analysis demonstrated that the isolate was Serratia marcescens. The optimal temperature and p H of the extracellular lipase were 60℃ and 8.0,which indicated that the lipase was a thermostable alkaline lipase. The optimal fermentation condition for high lipase production in flask were as follows: glucose 1.0%,beef extract 1.0%,Triton X-100 1.5%,olive oil 0.50%,Ca Cl20.50 mmol / L,the initial p H( 8.0) and temperature( 30℃),culture time( 96h).Under these conditions,the lipase activity was increased by 3.6 times.