Abstract: Objective To investigate thedifference of hypoglycemia in insulin-induced hypoglycemic stimulating GH secretion test between patients with primary and secondary hypopituitarism in order to cure hypoglycemia early. Methods A retrospective study was performed on sixty-three patients with hypopituitarism from June 2014 to June 2015. According to the pathogenesis, patients weredivided into primary group (n=47) and secondary group (n=16). The basicdata of patients, insulindosage, hypoglycemic time, hypoglycemic value, production of GH and compound F were recorded. Results No severe hypoglycemia and adverse effect was found in two groups. The basicdata in two groups had no (P> 0.05). The insulindosage (8.3±4.02) U vs (5.6±2.9) U, P=0.01, hypoglycemic time (22.1±4.8) min vs (25.3±4.5) min, P=0.027 and hypoglycemic value (2.42±0.48) mmol/L vs (2.04±0.59) mmol/L, P=0.032 in two groups had statistically significantdifference. The production of GH at 0, 30, 60, 90 min in two groups had statistically significantdifference (1.333±2.558)μg/L vs (0.059±0.024)μg/L; (1.885±3.392)μg/L vs (0.061±0.027)μg/L; (3.08±4.155)μg/L vs (0.056±0.017)μg/L; (1.856±2.94)μg/L vs (0.071±0.042)μg/L, P=0.000. The production of compound F at 30, 60, 90 min in two groups had statistically significantdifference (255.170±109.087) nmol/L vs (172.013±153.861) nmol/ L; (405.780±184.832) nmol/L vs (171.912±154.548) nmol/L; (330.092±147.754) nmol/L vs (128.400±114.567) nmol/L, P< 0.05. Conclusion Compared with primary hypopituitarism, the secondary hypopituitarism is prone todevelop severe hypoglycemia, with prolonged hypoglycemic time and worse pituitary function.