We discuss the direct theory of Baskakov-Durrmeyer operators Ln (f ) in uniform approx-imation and the equivalence bettween the derivative of Ln(f ) and the muduli of smoothness, then we extend the direct theory to a class of combinations of Ln(f). We obtain the charac-terizations of multidim ensional Baskakov-Durrmeyer operators in uniform approximation.