The surfaces of wood powder polyethylene composites(PE WPCs) with different wood powder content were treated by jet plasma discharge under air atmosphere to improve its adhesion properties. To study the effect of wood powder content on time efficiency of plasma surface treatment for PE WPCs, the surface properties change over storage time were studied by assessing the contact angle and bonding strength, as well as implementing Fourier transform infrared(FTIR) spectroscopy, and X ray photoelectron spectroscopy(XPS). The results show that the surface contact angle for the composites decreases, and the oxygen containing groups are introduced on the surface of the composites after plasma treatment, which results in the improvement of bonding strength. With the increase of storage time for plasma treated sample, the amount of oxygen containing groups reduces, the surface contact angle for the composites increases, and the bonding strength for the composites decreases slightly, which shows a certain extent of loss of efficiency of the plasma surface treatment. The content of wood powder in PE WPCs has a certain influence on the time efficiency of plasma discharge on the surface of PE WPCs, and the higher content of wood powder is contained in the composites, the less loss of time efficiency of surface plasma treatment can be achieved. Despite the time efficiency for the plasma surface treatment, the adhesion strength of the plasma discharge treated samples is still far better than that of the untreated samples.