1.The relationship between polhode and herpolhode of the instant center of a rigid body when it makes a plane paraller motion is presented.

1.给出了刚体在行运动时，刚体瞬的本体与空关系的一种证明方法.

2.A certification method to the relationship between polhode cone and herpolhode cone is given when the rigid body is in a fixed point motion.

2.摘要给出了刚体定点运动时本体与空关系的一种证明方法。