n this paper, the Coulomb collision effect of electron-ion is investigated based on the equilibrium bi-Maxwellian anisotropic distribution function in dense and unmagnetized plasma. An analytical expression is derived for the real frequency and the growth rate of the Weibel instability for two limiting cases jn ¼ kxjjh0jj j 1 and jnj 1. In the limit jnj 1, the quantity g that is due to a collisional term will appear in the growth and condition of the rate of the Weibel instability, which leads to a constraining condition of the growth rate. When g increases, the growth rate will increase and the wave instability will be distant from its own damping mode
