G=(V, E)爲一簡單且無方向圖形。圖形G之獨立集爲點集V之一子集合S，且使得S中任兩點在G中均不相連。若一獨立集不爲其他獨立集之真子集，則稱此獨立集爲最大獨立集。在本篇論文中，我們確定了林圖中最大獨立集之第三大數值。除此之外，我們亦描繪出達到此值之所有極圖。

Let G = (V, E) be a simple undirected graph. An independent set is a subset S of V such that no two vertices in S are adjacent. A maximal independent set is an independent set that is not a proper subset of any other independent set. In this paper, we determine the third largest number of maximal independent sets among all forests. We also characterize those extremal graphs achieving this value.