Abstract: A pen holder with puzzle blocks comprises a plurality of rotatable blocks on a holder stem with all lateral faces providing a groove respectively, a plurality of sliding pieces with different colors, numbers, or figures on the upper faces. The plurality of sliding pieces are fitted with the plurality of rotatable blocks on the grooves at all lateral faces and one of the grooves is left as a vacancy. During operation, the plurality of rotatable blocks are turned, respectively, and the vacancy is filled with an adjacent sliding piece. The process is continued until the four lateral sides of the pen holder are each aligned with one distinguishable color, number or figure.