During the design stage, tire designers have to use trial and error to decide on the design factors in order to satisfy performance requirements, and this involves a great deal of time and expense. Optimization is one of the methods which can be used effectively and efficiently to improve tire performance. There is a lot of literature available about optimal tire contour and structure design. On the other hand, there is little published information available about optimal tread pattern design. In particular, there is little information available about the interaction between optimal tire contour and tread pattern design. In this study, we constructed a tire optimization system in which the design factors of cross-sectional contour and tread pattern shape could both be dealt with as design variables at the same time. This optimization system was then applied to and verified for an actual tire design problem.