Yongchun attends to defense and offense simultaneously.In heart cultivation method and hand technique, it covers both left and right and makes offense and defense with appropriate strength in the shortest distance and time.The midline theory of Yongchun is to attack opponent with the shortest distance in offense and in defense guard the midline with a watershed approach to offset opponent's shortest distance attack.The mental cultivation method of force controlling is to regulate opponent's force by bridge hand connection and then attack others with change of direction, which is a typical fighting of Yongchun.“Making offense while defending” means to make counterattacks within possible range changing from being passive to active while offset opponents’ attack force.Besides, the following points must be taken into account during offense and defense: Firstly, they can not hand over the required range of defense, namely they need not to handle the mishit.Secondly, they can not leave the defense range to chase after opponent's bridge hand.Thirdly, the center of gravity must remain steady when they make moves and do not have to resort to force position.“Appropriate strength” is the most important force-making way in Yongchun offense and defense.The force is brief and explosive and is able to burst out strong lethality in a short time within a short distance, which exerts an important influence in Yongchun offensive and defensive system.