Abstract: The double projection neurons from cat's lumbosacral enlargment were identified by antidromic stimulation of both the cervical dorsal column and the dorsolateral column and stained intracellularlly with horseradish peroxidase.The cell body,dendritic arbors and their gemmules and the local laterals of the cell's axon were revealed completelly。The cell body and the gemmules dendrite were analysed and measured by the Pericolor 2001 type. The cell body was located in Laminae Ⅲ—Ⅴ.All the dendritic arbors situated nearly in Laminae Ⅲ—Ⅴ too.There is a ratio of 4.5 to 1 to 2.8 in rostrocaual,mediolaterel and dorsoventral length of the dendritic arbors.Axon collaterals arborized extensivly and issued varicositylike terminal branches in Laminae Ⅲ—Ⅴ,both within and beneath their dendritic territories and ventral to the cell body.The length and width of the the cell body are 58.25 and 51.04 um。The lenght and width of dendritic gemmules ranged from 1.15 um to 4.97 um(X=2.62um)and 0.78 um to 3.27um(X=1.93um)。Length-width ratio is 1.51±0.26.The length of pedicel of the gemmules ranged from 0.49-10.87um(X=2.56um).

Key words: spinal cord, double projectional neuron-dendritic arborn, axon collateral, dendritic gemmule