Total spinal block was induced by 2% lidocaine in adult mongrel dogs, and its influence on the respiratory, circulatory, endocrine and metabolic systems was studied. HR, MAP, CI and LV dp/dt max during total spinal block decreased significantly compared with those during the control period. The blood gas, Qs/Qt and ETVI were hardly influenced by total spinal block. Regarding the endocrine and metabolic systems, plasma renin activity (PRA) was significantly elevated by total spinal block, while plasma epinephrine and norepinephrine levels showed no changes. Blood levels of lactic acid, pyruvic acid and blood sugar were not influenced by total spinal block.