<正> Activity of succinic dehydrogenase（SDH）and acid phosphatase（AcPase）of effector-target cells during the process of LAK cells killing HR8348 cells was estimated by enzyme cyto-chemistry technique.SHD positive granules and AePase gray level were assayed with MIAS-300image analyser.The results showed:（1）After cocultivation of effector and target cells for vari-ous times

the activity of AcPase of HR8348 cells was apparently higher than that of the controlgroup

and it increased following prolonged coincubation.SDH activity of target cells increasedmarkedly within 30 and 60 rain cocultivation

but became low after 90 min treatment.（2）Ac-Pase content within LAK cells at 60

90

120

180 and 240 rain cocultivation was significantlyhigher than that of control group（P<0.01）.The phenomenon of high AcPase and SDH activitywithin effector-target cells indicates that the function of the two types of cells was in an activestate.At the early stage of effector-target combining

the increase of SDH with HR8348 cellsmay be related to defensive function of the target cells.Higher AcPase activity of target cells in-dicates the activation of lysosomal enzyme which serves as the material basis for autolysis of thecells.