We propose a specification test of parametrically specified nonlinear model against a weakly specified non-nested alternative. We estiamte the alternative model by using nonparametric regression (nearest righbours). The test is based on the t-statistic of an aWe propose a specification test of parametrically specified nonlinear model against a weakly specified non-nested alternative. We estiamte the alternative model by using nonparametric regression (nearest righbours). The test is based on the t-statistic of an artificial regression. Monte-Carlo simulations suggest that the test has good power and size characteristic.[+][-]