Objective To accumulate data and experience for the prevention and control of mushroom poisoning through investigation and summary of one mushroom poisoning caused by a new species:Amanita subpallidorosea, which was collected from Wuchuan County, Zunyi City, Guizhou Province. Methods Epidemiological investigations were carried out soon after the mushroom poisoning incident occurred. Suspicious mushroom specimens were photographed, recorded and collected, species identification and acute toxicity test were taken subsequently. Results On September 19th, 2014, one father and his son from rural area of Wuchuan County developed symptoms of nausea, vomiting, abdominal pain, and diarrhea in 9 hours and 17 hours after eating some white wild mushrooms collected by themselves from the forest just behind their yard. The two patients developed acute liver failure and their main symptoms were as follows:the highest alanine aminotransferase of case 1 reached 1 279 U/L, and case 2 was 6 070 U/L; the aspartate transaminase of case 1 reached its peak at 2 829 U/L, and for case 2 was up to 6 868 U/L. Since the diseases were aggravated, several abnormal clinical indicators of patients appeared and the two patients died on the 5th and 7th day after poisoning due to multiple organ failures. Based on morphological and molecular studies, the suspicious mushroom was identified as a new lethal species, Amanita subpallidorosea. All the tested 5 male mice and 3 out of 5 female mice died in the acute oral toxicity test. Conclusion This food poisoning incident was caused by the lethal mushroom, Amanita subpallidorosea, which was mistakenly regarded as edible mushrooms.