Abstract: Lactate dehydrogenase (EC 1.1.1.27) is an oxidoreductase which catalyzes the resversion conversion of phruvate to lactate.The five isoenzymes of lactate dehydrogenase are tetramers composed of four polypeptide chains of two types subunits A and B (or M and H).The five isoenzymes have been demonstrated in all mammalian tissues,cells and serum.Tree shrew is a specific kind of animal between insectivora and primate.It is one of the most suitable research materials for experimental medicine,experimental pathology and evolutional biology.The present paper deals with the analysis by agarose gel electrophoresis of lactate dehydrogenase isoenzymes of eight different tissues of tree shrew (Tupaia belangeri chinensis).The eight tissues are:heart,lung,submaxillary gland,spleen,kidney,adrenal gland,skeletal muscle and brain.The electrophoresis was performed on 0.5% agarose gel thin layer in a Ph 8.6 buffer containing 0.06 mol/L sodium diethylbarbiturate,0.2 N hydrochloric acid.The isoenzymic activity was visualized with a stanining solution consisting of sodium DL-lactate,nicotinamide adenine dinucleotide (NAD),N-methylphenazinium methylsulphate (PMS) and nitro-tetrazolium blue chloride (NBT).The electropherograms of LDH isoenzymes was scanned record at λs=570 nm and λr=500 nm,scanning speed for 20 mm/min.Five different molecular forms of isoenzymes and alterations of isoenzymic patterns were obserbed in the eight tissues of tree shrew.The isoenzymic phenotypes of five molecular forms are LCH1,LDH2,LDH3,LDH4,LDH5,in heart,submaxillary gland and brain,only the phenotype of skeletal muscle were LDH5,LDH4,LDH3,LDH2,LDH1.The LDH4 to LDH1 isoenzymes migrated towards the anode and LDH5 isoenzyme toward the cathode in the Ph 8.6 buffer.LDH1 is the fastest and LDH5 the slowest in the electrophoresis.The mean values of the five components of LDH isoenzymes in eight itssues were measured.The percentage of H subunit was calculated with the formula H%=LDH1%+3/4 LDH2%+1/2 LDH3%+1/4 LDH4%.The H/M subunits ratio was 2.3,0.9,1.5,1.0,1.6,0.94,0.55 and 1.8 in above mentioned eight tissues,respectively.