A method is described for staining lactate dehydrogenase(LDH) and esterase (EST) isozymes on the same slab gel. By utilizing the noninterference of two kinds of isozymes in their staining reaction and the difference in their colour, LDH and then EST were stained successively, resulting in distinct bands of both isoenzymes on the same slab gel. The band patterns of either enzyme on the same slab gel were completely the same as those on separate slab gels. Being able to save reagents,time and cost necessary for isozymic analysis,and convenient for the identification and comparison of different samples, this is an economical and efficient staining method, which can also be applied to staining malate dehydrogenenase (MDH) and EST isozymes on the same slab gel.