The work aims to improve the microstructure of TiCN films and further increase hardness and adhesion. TiCN films were prepared with arc ion plating technology by changing the amplitude of pulsed bias. Surface and cross-section morphology, phase structure, chemical bonding structure and composition of the films were observed, analyzed and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS). The hardness of the films was measured by micro Vickers-hardness tester, the thickness was examined by 3D profiler, and the scarification test was carried by multifunctional material surface tester.Hardness, adhesion, texture and deposition rate of the films were strongly affected by pulsed bias. With the increase of pulsed bias, the grain size of TiCN films gradually refined and the deposition rate and adhesion strength firstly increased and then decreased, but the hardness of TiCN films kept linear growth. When the pulsed bias was –200 V, the new phase of C3N4 appeared in the TiCN films. The hardness and adhesion strength of the films greatly increased and the surface morphology changed suddenly and generated the most droplets. When the pulsed bias was –250 V, TiCN films showed the best performance , the droplets on the surface decreased obviously, the hardness was 4017HV and the adhesion strength was 51N.Pulsedbias has certain effects on the existence of microstructure and carbon in the films. Changing the pulsed bias properly can densify the microstructure of TiCN films and form the dispersion hardening phase to provide higher hardness and adhesion strength for films.