Objective To analyze the content of 6 kinds of amatoxins in 3 species of Lepiota collected from Chuxiong of Yunnan Province.Methods The collected mushrooms were baked and dried at 45 ℃， and species identification was carried out by morphological and molecular biology methods. The mushrooms were divided into three different growth periods （growth period， mature stage， aged stage） and different tissue parts （pileus， stipe， whole）， and the toxins were extracted by ultrapure water ultrasound. The determination was performed by ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry with electrospray （ESI^-） in multiple-reaction monitoring （MRM） mode， and the content was quantitatively analyzed by external standard method.Results No amatoxins were detected in Lepiota clypeolaria and Lepiota cristata， while α-amanitin and β-amanitin were detected in Lepiota brunneoincarnata， and the content of α-amanitin was higher than β-amanitin. The total content of α-amanitin was highest in the mature stage （1.67 mg/g）， followed by the grow stage （1.56 mg/g） and least in the aged stage （0.40 mg/g）. And the total content of β-amanitin was also highest in the mature stage （0.71 mg/g）， followed by the growth stage （0.60 mg/g） and lowest in the aged stage （0.14 mg/g）. The cap part was richer in α-amanitin and β-amanitin than the stipe part in the growth and mature stages， while the content of α-amanitin and β-amanitin in the aged stage was higher in the stipe than in the pileus.Conclusion In Chuxiong Prefecture， Yunnan Province， the flesh-brown ring-stalk mushroom L. brunneoincarnata mainly contains Amatoxins， including α-AMA， β-AMA， Amanin， and Amaninamide， excluding phalloidin and virotoxin. The content of α-AMA and β-AMA varies in different growth periods and tissues， providing reference for the clinical diagnosis and treatment of poisoning by this type of mushroom.