This slide blade type ic engine having no piston comprises a rotor, a dynamic slide blade, and a special cylinder. The rotor and the dynamic slide blade separate the cylinder into four regions of which each performs four strokes respectively, i.e. intake, compression, work-done and exhaust, during each revolution of the rotor. When a region finishes doing work, the next region succeeds in turn to do work, and thus work is done four times per revolution. The invention avoids the defect of present piston crank and has no such discontinuity of work done as current single cylinder. This invention combines the mechanism of ic engine with that of steam engine in one entity, fully utilizes the exhausted waste heat energy, dynamic energy and heat energy which cools the engine, and greatly increases the heat engine efficiency.