Granules of the submaxillary gland of the white mouse contain both kallikrein and renin. The granules were separated and concentrated in sequential centrifugation procedures. They were more stable at room temperature and in hypertonic sucrose solutions than in the cold or in isotonic solution. The amylase, acid phosphatase, renin, kallikrein, and benzoyl-L-arginine ethyl ester esterase contents of the granules were determined. Kallikrein and renin showed a similar distribution pattern after fractionation. Granular renin released the equivalent of 9.6 μg angiotensin II amide/mg enzyme protein/min from swine serum angiotensinogen. Granular kallikrein liberated from human kininogen the equivalent of 8.4 μg bradykinin/mg enzyme protein/min.Electron micrographs of the isolated granules showed various forms; some were spherical and symmetrical, and others were amorphous.