Abstract: A test for the seed of pigeon pea Cajanus cajan (L.) Millsp grain impunity from insects was conducted by the two wrapping methods in which pigeon peas seed grain were wrapped in ventilative and sealed industrial steaming cooking plastic bags respectively. Treating wrapped grains with Co 60 with radiation dosages of 0 KGY, 0.1 KGY, 1.0 KGY, 3.0 KGY and 7.0 KGY, the result shows: a) wrapped by ventilative wrappings and treated by Co 60 with dosage of 3.0 KGY, the grains have the best impunity from insect. On an average, only 0.87 grains was susceptive to insects; b) wrapped by ventilative bags and not treated by Co 60, average 46.87 grains were susceptive to insects; c) wrapped by sealed plastic bags and not treated by Co 60, average 1.13 grains were susceptive to insects. Meanwhile, the nutritional content in grains did not change after radiation treat. Therefore, considering economic factor, the purpose to prevent from grain insect can be reached by non radiation and sealed wrapping treat.