The authors have used non-laying and laying hens (Lohmann Brown), in order to study morphological aspects development of tunica mucosa of the oviduct. The results showed that the oviduct of the hen is well-developed at the left side, atrophied at the right side and consists of five different regions: infundibulum, magnum, isthmus, shell-gland and excretory section (vagina). During 1-120 days in oviduct is the most advanced caudal part, where height and width folds of a tunica mucosa is more than in cranial part, that probably, is caused with the future function of these departments. In the period oviposition (150-540 days), the tunica mucosa is most advanced in such departments, as: magnum, isthmus, shell-gland