The effects of laser fluence on the structure and properties of the reactive pulsed laser deposited carbon nitride (CNx) thin films prepared at different gas pressures of N2 and NH3 were investigated. The structure, the morphology and the chemical composition of the films were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Rutherford backscattering and Fourier transform infrared. The films were plane, adhesive and relatively hard, with a low droplet density. The deposition rate decreases with increasing gas pressure and laser fluence, while the N/C atomic ratio increases. The nitrogen concentration in the deposited films drops when the substrate temperature is increased, indicating a desorption process of the CN radicals. Spectroscopic studies of the plasma plume indicates an interesting correlation between the CN band emission intensity and the nitrogen concentration in the samples.