The results of the studies confirmed the presence of Bracken poisoning in Taiwan. Among three natural affected cases, two showed the symptom of hematurea Visicalis and one showed hemorrhagic diathesis syndrom. The clinical pathological changes in artifitial induced intoxication includding blood coagulating disorders with reducing WBC, RBC and thrombocyte count, and increasing the bleeding time and SGOT value in plasma. Reduction of the ratio between granulocyte and lymphocyte also being observed in clinical phase of intoxication. Severe hemorrhages in serosa and mucosa of various organs was the most prominance of lesions in bracken poisoning. The above mentioned changes can be taken as valuable diagnostic parameters of Bracken poisoning.