For a determination of soil characteristics one should have access to instruments that can measure these characteristics, including: soil penetration resistance with high accuracy. One of the accurate instruments commonly employed in soil penetration determinations is cone penetrometer. This apparatus, by measuring soil cone index at different soil depths can provide useful about information about the soil. In this research a digital cone penetrometer was designed and fabricated. For a later evaluation of the apparatus, tests were carried out on grassland with three levels of moisture content (13%, 34% and 86%). The accuracy of the displacement and force measurement setups were recorded as 0.01 mm and 1.96 N, respectively. Based on the results of the experiments, with an increase in grassland (muskeg) moisture content, soil penetration resistance, increased, such that with an increase of a low level of penetration force, penetration increased greatly. Value of critical pressure at a level of moisture content of 13% was more than those at the other levels of moisture contents.