The results of shear strength parameters of soils from Chalakówka, Owczary and Szymbark are presented in the paper. Determination of the influence of moisture content on values on values of angle of internal friction and cohesion and assessment of usefulness of Matsushi-Matsukura method for evaluation of shear strength of unsaturated soils were the subject of the tests. Shear strength tests were carried out in standard direct shear box on samples of dimensions 60 × 60 × 19 mm. Results of tests revealed that the increase of moisture content causes decrease shear strength of tested soils, which mainly is caused by the decrease of cohesion. Values of shear strength determined using Matsushi-Matsukura method give good agreement with results of shear tests in case of majority of tested soils.

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