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We suggest a control scheme for choosing populations of molecular rotational states by wave packet interference. The rotational wave packets of LiCl molecule excited non-adiabatically by half cycle pulse (HCP) is controlled using the second ultrashort HCP. By adjusting the time delay between the two laser pulses, constructive or destructive interference among these wave packets enables the population to be enhanced or repressed for the specific rotational state. The role played by the field strength and the pulse duration is also calculated numerically. We have used fourth order Runge-Kutta method to study non-adiabatic rotational excitation (NAREX) dynamics.Keywords. NAREX; delay time; wave packet interference.inserting the equations (8) and (9) into equation (7), one obtains a set of coupled equations for the timedependent expansion coefficients,The selection rules J = J ± 1 and M = M simplify the differential equation (10) asandThe time-dependent rotational wave packet (8) is thusThe matrix elements J M i | cos (θ) |J M i for J = J ±