An improved frictional interconnecting toy block arrangement having a hollow body means fabricated of a semi-flexible material such as a blowmolded plastic. The interconnecting of the toy blocks with each other is achieved by female coupler means and male couplers. The male couplers are part of the body means and unitarily fabricated of blowmolded plastic during the fabrication of the body means. The female coupler means are fabricated of a more rigid plastic such as an injection molded plastic which can be fabricated to close tolerances. The female coupler means fits and is retained within apertures molded into the walls of the body means. Relief means, such as slots, are provided in the female coupler means to allow for dimensional variations of the male couplers that are inherent in the blowmolding process and still provide interlocking with the male couplers. In addition, the relief means and flexible nature of the male coupler allow the blocks to be easily interconnected with each other and removed from each other by young children whose strength and/or manual dexterity have not yet fully developed.