The chip behavior that means the sticking to the cutting edge, the movements after cut, the flying directions and so on influences tool wear and surface finish quality in dry hobbing. The transient phenomenon of chip generation and behavior in milling with flytool are investigated by using high-speed video camera. Three typical chip generations, which are grouped in chip's curvature and flight ways, are observed in milling tests by the cutting edge of helix angle 0°. The chip's flight course changes by the tool tip materials into higher or lower flights. The phenomenon that the chip sticks to the rake face and it connects to the chip produced newly by pressure during next cutting is also observed. Chips stick easily to the rake face of cemented carbide tools. Under the conditions of lower cutting speeds less than 200 m/min and low hardness materials such as annealed or normalized low carbon steels, chips also stick easily to the rake face. The chip changes flight course by the location of ending point of cut on the fly tool.