Ultrasonic velocities and densities of the binary liquid mixtures of N-methyl-2-Pyrrolidone (NMP) with Cyclohexylamine (CHA), Cyclohexanol (CHOL) and Cyclohexene(CHE) at a temperature range of 303.15 to 318.15 K over the entire composition range were measured. The theoretical values of ultrasonic velocity were evaluated using the Nomoto's relation(UNR), Impedence relation(UIR), Ideal mixing relation(UIMR), Jungie's relation(UJR) and Rao's specific velocity relation(UR).The molecular interaction parameter (α) was computed by using the experimental and theoretical ultrasonic velocity values. The variation of interaction parameter with the composition of the mixture has been discussed in terms of molecular interactions.