The silane coupling agents, γ-amino-propyltriethoxy silane, were used to improve interfacial bonding between polymer and whisker in preparing for the composite. Potassium hexatitanate whisker which the surface was treated by the contents of silane coupling agent and polyacetal were melted and mixed for 30 min at 165℃, and the specimen was synthesized by injection molding. The composite which is blended with whisker of 30 wt% treated by silane coupling agent of 0.6 wt% was the maximum in mechanical properties. This means that the functional groups of silane coupling agent were enhanced wettability between polyacetal and whisker.