Objective To evaluate the diagnostic valu e of ~131I-MIBG adrenomedullary scintigraphy for high blood cat echolamine. Methods 96 cases of high blood catecholamine and 197 cases of other diseases were screened with ~131I-metaiodo benzylguanidine(MIBG) adrenomedullary scintigraphy. Results 56 cases of the total 60 cases of pheochromocytoma and 33 cases of the total 36 cases of adrenomedullary hyperplasia showed positive image. The positiv e rate were 93.3% and 91.7% respectively. 138 cases of primary hypertension, 4 9 cases of adrenal and other organic tumor, 4 cases of pheochromocytoma befor e operation, 10 cases of cured pheochromocytoma after resection and 3 cases of adrenomedullary hyperplasia all showed negative image. The total positive rate for high blood catecholamine was 92.7%, which was much higher than other method s, such as biochemical assay, type B ultrasound, computer tomography and magneti c resonance image. Conclusions ~131I-MIBG w as of great value for the locative and qualitative diagnosis of high blood catec holamine,especially for the silent, ectopic and multiple pheochromocytoma, the m etastatic malignant pheochromocytoma and adrenomedullary hyperplasia. It could be used for the differential diagnosis of high blood catecholamine from primary hypertension and other kinds of tumors.