The present invention provides a protective cover structure for a rammer for which a guard cover plate of a power engine in a rammer is molded from a synthetic resin allowing any shape to be freely obtained and having small weight, high strength, and impact absorption ability. The cover plate is configured so that it can be assembled and disassembled by simple operations, has good endurance with respect to severe vibrations and can reduce the damage of the machine body due to the adequate impact absorption ability even when the rammer tumbles.Front end sections of guard covers disposed on both sides of a power engine are joined and fixed to the front surface section of the crank chamber, lower sections of the rear portions are supported by support frames of a protective stand provided at the lower surface of the power engine, and the rear sections of the rear portions are linked integrally by a linking transverse pole.