The cellular distribution of two calcium binding proteinswere investigated by peroxidase - antiperoxidase method with theaid of monoclonal antibody specific for calbindin-D28K (CaLB) andparvalbumin (PV) in the brain of the treeshrews, Tupaia glis.Eight adult treeshrews weighing 130-200 gm were divided into 4groups : CaLB - cross section, CaLB - sagittal section, PV -cross section and PV - sagittal section. The result found thatimmunoreactive CaLB and PV have a widespread distributionthroughout the brain and were present in most of the neuronalcell groups. The immunoreactivity was observed within theperikarya, dendrites and axons. The two proteins are generallyexpressed in different neurons with some neurons containing bothproteins such as Purkinje cell of cerebellum and neurons intrapezoid nucleus. In this study, CaLB neurons are prominent inthalamus, hypothalamus, limbic system, sensory system, superiorolive, olfactory system, trapezoid nucleus, medial geniculatenucleus, visual system, cerebral cortex, cerebellar cortex andextrapyramidal system. PV neurons are prominent in pyramidalsystem, reticular formation, cerebellar nuclei,cerebellar cortex,cerebral cortex, vestibular system, hippocampal formation andextrapyramidal system. These two proteins were limited primarilyto neuronal element and some ependymal cells, and were absent inglial cells. It can be concluded from this study that these twoproteins are distributed almost in differrent neuronal cell groups.