By using the 500N microcomputer control material testing machine, based on the load-depth curve, the hardness of the grains was experimentally studied adopting needlepoint pressing-in method. The peas, horsebeans, rice, mung beans, wheat, lentils as well as corn at different moisture and component parts were tested and analyzed, with the measured hardness range of 2～75MPa. The research showed that at the loading speed in 0.25～2.00mm/s and depth of indentation in 0.25～1.50mm, no obvious effect appears in the test results. The taper of needlepoint and the value of grain hardness have a quantitative relation in the measurement.