Abstract:The influence factors of machine tool system on milling stability are analyzed using the Altintas's machining chatter theory for realizing forecast. It was found in study that milling stability lobes would be influenced by mode parameters of spindle -tool system, especially as mode stiffness, damping ratio and natural frequency. In addition, through the analysis of the influence of system dynamic stiffness under the same combination with different damping ratio and modal stiffness on milling stability, it was found that the influence of modal stiffness on milling stability was greater than that of damping ratio. Tool parameters, material characteristic of workpiece, cutting parameters and their influence law on milling stability were analyzed separately. Results show that less tool teeth and smaller helix angle and tool elongation are helpful to avoid milling chatter, as well as enlarge tool diameter. Machining workpiece with smaller tangential and radial cutting coefficient of material can be more stable than the other. Also, there are larger critical cutting depths of the system with smaller cutting width and up milling method.