Aim To prepare insulin powder for inhalation by spray-drying technology, determine the deposition of the insulin powder formulation in vitro and preliminarily investigate hypoglycemic response of the dry powder with/without absorption promoters. Methods The depositions of the insulin powder for inhalation were determined by the China Pharmacopoeia 2000 version addenda XH and hypoglycemic effects were evaluated by testing serum glucose with glucose oxidase-peroxidase (GOD-PAP) method.Results The depositions of the spray-dried insulin powder for inhalation were more than 40% under significantly greater decline in blood glucose levels, while coadministration with 1% sodium caprylate, 1%effect ( P ＞ 0. 05 ). Conclusion Insulin powder for inhalation was relatively stable under various humidity pulmonary route.