By means of agar immunoelectrophoresisand antigen antibody crossed electrophoresis (Laurell), protein components in endolymph and periymph of guinea pig inner ear were analized. 1) Agar immunoelectrophoresis: Three to four components in endolymph and 4 to 5 components in perilymph were observed with Amido Black 10B staining. In these precipitates of both fluids, each component of Al-and *-Gl fraction was stained with periodic acid Schiff reagent.According to the mobility of serum protein components and glycoprotein staining, Albumin, Haptoglobin, Transferrin, and *-Globulin were determined.2) Ag Ab crossed electrophoresis: Three to five components in endolymph and 5 to 7 components in perilymph were observed with Amido Black 10 B staining. Albumin showed the largest arc in all of them. *-Globulin found appeared skew and showed weak arc at the negative pole. Several unknown arcs were found on *-and *-Gl fraction.A/*-G was 1.50 in endolymph and 1.52 in perilymph.From these results obteined, it is probable that protein components in serum and those in inner ear fluids were different, and high molecular protein components were poorer in inner ear fluids compared with serum.