Electrophoretic analysis has been made of 12 normal rabbit-sera by the moving-boundary-method of Tiselius. Mobility-measurements at pH 7.8, 0.2 ionic strength, and 1 C show coefficients of variation for the individual components somewhat less than the analogous findings with a similar series of normal human plasmas. Composition of the sera is reported in terms of the respective areas under the various component-peaks of the refractive index-gradient-curves produced by the method of crossed slits. Gamma-globulin areas were subject to the greatest variation, the maximum being that between 13 and 29½ per cent of the total protein. The variation in amount of beta-globulin was of less magnitude, but in several instances the boundary split into 2 and possibly 3 parts which varied greatly in relative size from one experiment to the next. The alpha-globulin of rabbit-serum moved only slightly slower than the albumin, and good separation was difficult to obtain, particularly in cases where the albumin-content was high. Separate area-measurements were possible in 3 cases where the alpha-globulin constituted 5.5, 7.5, and 7.9 per cent of the total protein. The globulin-content of these 12 sera was about 10 per cent higher than that reported for another group of normal rabbits by Seibert (3). It is possible that such differences may be due to species-variation or to differences in diet. Nevertheless, the individual variations found here are much greater than this group-variation, emphasizing the difficulty of establishing a normal pattern.