The relation of the concentration of neutral fat, phospholipid, free cholesterol and cholesterol esters of blood plasma, the red blood cells and the white blood cells of man to increasing percentages of total lipid in each of these respectively was determined by oxidative micromethods in a series of more than 900 lipid extracts. A parallel increase in all four lipids was noted with increasing amount of total lipid in plasma until the total lipid exceeded the normal range. The earliest manifestation of a lipemia was a precipitous increase in plasma neutral fat and no increase or a decline in plasma cholesterol esters which later rose again as the lipemia developed. Increasing amounts of total lipid in the red blood cells was found due chiefly to phospholipid; although when the total lipid exceeded the normal range appreciable amounts of neutral fat appeared, the increase in cellular lipids bearing no direct relation to increases in plasma lipids. The same relation was established for the white blood cells as for the red blood cells but the leucocytes contained considerably more lipids than either plasma or the red blood cells.