To obtain a compsn. having a high impact strength, a high elastic modulus, an excellent surface smoothness and a high internal loss by blending a specific amt. of an aluminum borate whisker with an aliph. polyketone resin.

This is a resin compsn. obtd. by blending 10-250 pts.wt. of an aluminum borate whisker with 100 pts.wt. of an aliph. polyketone resin, i.e., a thermoplastic resin having a linear structure wherein an olefin and carbon monoxide are polymerized completely in an alternative manner. Furthermore, a stabilizer such as an antioxidant, an ultraviolet light absorbing agent, a lubricant, a flame retardant or a plasticizer is optionally blended. The aluminum borate whisker is of a fiber diameter of 0.05-5 μm and a fiber length of 2-100 μm, and has a representative compsn. indicated by the formula: 9Al2O3.2B2O3 or 2Al2O3.B2O3. Its surface is pref. subjected to a surface treatment with a silane coupling agent to enhance the compatibility and adhesion of the aluminum borate whisker with resin.