In this thesis, the dynamics of unbalanced rigid rotor is analysed. Instead of obtaining experimental data on real rotor, the analysis of rotor dynamics is performed with numerical simulation. First, mathematical model of a rotor is developed. Then the rotor dynamics and equations of motion are derived. The result of simulation are time dependent reaction forces in bearings. Based on reaction forces analysis, two plane balancing of a rotor is presented and performed. In the second stage the oscillation of two degree of freedom rotor model in supports is analysed. The result of the simulation are vibrations in rotor supports. Based on the oscillation speed in supports the rotor is categorized in the quality zone by standard ISO 10816-1:1995.