南湖柳葉菜是臺灣的固有物種，其分佈呈現高山島嶼化的型式，生長在高海拔的岩屑地上，棲地選擇嚴苛。本研究利用同功酵素電泳的方法檢驗其族群遺傳結構，在分析了15種同功酵素中，判讀了20個基因座，各基因座上的平均對偶基因數是1.24個，其中帶有多型性基因座的僅有4個；異合度(He)為0.074，顯示南湖柳葉菜的遺傳變異度不夠豐富。在遺傳形質的分佈上面，南湖柳葉菜的遺傳變異度僅有11%是存在於族群間，族群內的遺傳變異度高達89%。族群間的遺傳分化指數(Fst)是0.11，基因流傳值(Nm)是1.48(>1)，這表示此物種的基因流傳不受阻礙，造成族群間有中度遺傳分化的力量可能來自地域性的天擇壓力。由群叢分析的圖中得知，奇萊山地區族群保有最豐富多變的遺傳組成，但也和臺灣南、北兩地的遺傳距離最遠，而南、北兩個族群間幾乎沒有分化，由於南湖柳葉菜是多年生而且異花授粉的物種，皆有利於其在遺傳變異上的保留，故推測此物種在過去曾經發生先軀者效應而使得其遺傳形質有同質化的趨勢。天擇與基因漂變是影響南湖柳葉菜之族群遺傳結構的主要力量，而臺灣中部的高山地帶可能是此物種最原始的棲地。

Epilobium nankotaizanensis is an endemic species, know for only 6 populations in the high montain areas of Taiwan. Genetic variation within and among populations were determined by isozyme analysis. Electrophoretic data from 20 loci showed little genetic differentiation. The low heterozygosity in overall populations imply that E. nankotaizanensis is a species with nearly fixed gene pool. The inbreeding coefficient is high (ＦIS=-0.388) gene flow rates is high (Nm=1.48) when estimated from Ｆsr indirectly, and may suggests that E. nankotaizanensis is an outcrossing favorable plant. On the other side, these results may suggest that the origin population of E. nankotaizanensis in Taiwan was located at Chi-Lai Shan in the central part of this island, than seeds dispersed by wind to the other summits. Genetic ecological consideration of conservation, by means of habitats preservation for this species are urgently needed.