By theoretically analyzing dynamic behavior of the crankshaft, the rolling piston and the blade in rolling-piston rotary compressors, constraint forces and sliding speed at each pair of movable machine elements were obtained, and unbalanced inertia forces and compressor vibrations were evaluated. It was concluded that theoretical results have a good agreement with experimental ones. Moreover, it was revealed that one of major factors which cause compressor vibrations is speed variation of the crankshaft and compressor vibrations are not affected by rolling behavior of the piston.