The aim of this study is to evaluate the induced histological changes in the Islet of Langerhans and - cells. The ethanolic extraction of Artemisia Herba Alba (AHA) as 20 mg has been injected intraperitoneally (I/P) in induced diabetic (Injected rats intraperitoneal with a dose of 60mg/kg streptozotocin STZ) and normal Wistar rats. Three diabetic groups were selected, each consists of eight rats. Group one injected (I/P) with distilled water only; used as diabetic control, group two was injected with insulin subcutaneously (S/C), group three injected with Ether-extract of AHA (I/P), and group four selected from non diabetic rats, used as normal control injected (I/P) with distilled water. All groups were fostered for 21 day; then weighted and executed. The pancreases were taken and the histological preparations for haematoxylin & eosin (H&E) and immunohistochemistry have been done. The analyzed results showed that: the induced diabetes reduced the rats’ weight by 62.5% in average while the treatment by Insulin and AHA regain the weight up to 75% and 71.4% respectively. The induced diabetes reduced the -cells% per islet 56.8% while the treatment by Insulin and AHA increase the -cells% per islet 73.8%, and 73.4% respectively. The induced diabetes reduced the islet volumes from 1990 mm3 to 766.8 mm3, while the treatment by insulin and AHA regain the volumes up to 1730 and 1590 mm3 respectively. The microscopic results confirmed that: AHA stimulate and regenerate new -cells in islets of langerhans thus leading to increase the volume which enhancing the host weight gain.