Abstract: A roller-typed paintbrush's structural improvement is mainly comprised of a hollow grip made of plastic material and a hollow support, the first connection end of which is connected securely to the front side of the hollow grip, and another end of which is extended to left side and right side outwardly to become a first supporting arm and a second supporting arm, inside front side of both which is arranged an immovable axis; and two supporting wheels, which may be fitted into the immovable axis arranged pivotally at the first supporting arm and second supporting arm, and the inside part of both which may be inserted into the hollow roller arranged hair-sheath to be wedged in securely by a method of tight fitting, such that an objective of quick assembly or taking-apart may be achieved; since the invention is made of plastic material so, not only does it have the advantages of light weight and low cost, but also does it have the advantage of easy recycling to further fulfill environmental protection and automa