In this work, a 6 degree of freedom lumped mass model is constructed for an OHC-type cam valve train anylysis and the model is verified experimentally. Using the verified model an optimal cam profile is designed to minimize the maximum contact force between cam and follower under the constraints such as cam lift and cam event angle. The designed cam was carefully machined and tested experimentally. As operating the designed cam shaft on the testrig, the valve motion was precisely measured with laser displacement meter and the contact force was indirectly monitored by measuring strain at a certain point of the finger follower. Judging from the model simulation and experiment results, the maximum contact force can be reduced as much more then 20 percent under maintaining the original valve flow area by adopting the optimum cam profile.