Whole quinoa grain was separated into bran and milled grain, and the milled grain into perisperm and embryo. The proximate composition of the milled grain was similar to that of whole grain. The protein and lipid content of the embryo was 57% of total protein and 49% of total lipid, respectively. Mineral analysis showed that the quinoa grain was rich in K, Mg, Ca, P and Fe. The perisperm contained large oval starch aggregates 20–30 μm in diameter and polygonal granules around 1 μm in diameter. Differential scanning calorimetry data indicated a gelatinization temperature of 54.0 to 71.0°C and enthalpy of 11.0 J/g starch. The water-soluble protein and NaCl-soluble protein fractions composed 28.7–36.2% and 28.9–32.9% of total protein in each fraction. Unsaturated fatty acid accounted for 87.2–87.8% of total fatty acid. Phytate, a trypsin inhibitor activity and lipoxygenase activity in the embryo were highest. The saponin content of the bran was 86% of total saponin.