Dynamic Data System(DDS) methodology developed recently is applied to find a sensing factor for the cutting tool wear using the vibration signal of tool post. Experiments are carried out under 3 cutting conditions with a lathe. The material of testing insert is chosen as tungsten carbide coated with titanium nitride. Some factors, for example, variance, damping ratio, dispersion, and power of each dynamic mode obtained by Autoregressive Moving Average(ARMA) model are checked for a possible to the cutting toll wear. Physical meaning of the important frequency band is investigated by attaching the accelerometer to five other point around tool post.