This thesis deals with comparative studies to the determination of the liquid limit and the undrained shear strength of various soils. Two basic methods were used for the evaluation of the liquid limit, Casagrande percussion method and fall cone method. Five different types of soil were analysed for this investigation. The undrained shear strength of four different types of soil samples were conducted using the laboratory vane shear device and the fall cone apparatus. These kinds of tests yield values of the undrained shear parameter. Also in the laboratory vane shear test the influence of the rotation speed and the height of the vane on the undrained shear strength were assessed. Then further tests were conducted using the penetrometer and torvane by alternative. In order to be able to compare the results of the various shear tests, the soil specimens were produced in the same process with the equal density and water contents. Finally, the correlations with the appropriate test results were made for further interpretation.