The paper presents a modified method of measuring hardness of maize caryopsis marked as HVR. The essence of this method is a test carried out on the machine of Instron type with the use of Vickers microindenter. The test consists of four subsequent stages including an emptied elastic reaction of tissue. Hardness of border elements of caryopis structure of Labor maize, on account of mechanical properties that is fruit-seed coat and a seed was tested. Based on the research, which was carried out, parameters of the test were optimized including anatomical and morphological diversity of the tested object. The following optimal parameters of the test were determined: basic load of 10 N, duration of creeping stage 300 s and relaxation stage time 30 s.