NeomysisawatschensiswascollectedonthewestcoastofJiaozhouBay,Qingdaoin1992andacclimatedinthelaboratoryconditions.Theacutetoxicitymethodusing4~6dayjuvenilemysidofthisspeciesisstudied.ThespeciesiscomparedwithM.bahiaintaxonomy,geographicdistribution,morphology,aswellasthesensitivitytoAbstracttoxins.Basedontheresults,werecommendN.awatschensistobeastandardmarineorganismfortoxicitytestinChinaandthemethodtobeappliedintoxicityevaluationofdrillingfluids.Inthispaper,wereporttheresultsoftheabovestudiesandtheapplicationofthemethodintheevaluationofseveraldrillingfluidproducts.