We have studied theresonant two-photon ionizaition (R2PI) spectra of van der Waals complexes p-C6H4F2NH3...(ND3)through the S1←S0 transition withmass selectivity. Spectal analysis shows that the stretching frequencies of the complexesis about 86cm-1. From the photodissociation energy, we estimated the bond energy of the complexp-C6H4F2…NH3 in the S1 and S0 states. Abinitio calculation for p-C6/H4/F2/…NH3/ gives the following geometry: the N atom of NH3is located on the symmetry axis (Z-axis) and 0.353～nm above the benzene ring;the C3 axis of NH3is at an angle of 52.5° with the Z-axis of p-C6H4F2 withone of the hydrogen atoms pointing towards the benzene ring;the rotation of NH3around the Z-axis is nearly free. The calculataed bond dissociation energy and theprediction of internal rotation are consistent with our experimental results.