在平面几何中,我们有著名的蝴蝶定理(Butterfly theorem):设F是圆内弦PQ的中点,过点F作弦AB和CD,设AD和BC各相交PQ于点M,N,则F是MN的中点.笔者通过对蝴蝶定理的解读,尝试将其在抛物线中类比探索研究,得到:结论如图1,过抛物线x2=4my(m>0)的焦点F任意作两条弦分别与抛物线交于点A,B,C,D,连结AC,BD交直线y=m于M,N两点,则M,N关于点F对称. In plane geometry, we have the famous butterfly theorem: let F be the midpoint of the circular inner chord PQ, point F to be chord AB and CD, let AD and BC intersect PQ at point M, N, then F is the midpoint of MN. The author tries to explore the analogy of the butterfly theorem through the interpretation of the butterfly theorem. The conclusion is shown in Figure 1. The focal point F over the parabola x2 = 4my (m> 0) Respectively parabolic intersection points A, B, C, D, connecting AC, BD intersecting line y = m at M, N two points, then M, N about point F symmetry.