The present work was designed to investigate the characteristic features of histological changes that occurred in juxtaglomerular apparatus development of local domestic Iraqi sheep embryo and lambs Awasi sheep (Ovis aris) at different during gestation stages until birth. To conduct this goal, firstly the prenatal specimens from sheep embryo collected from 12 female's pregnant ewe at three different ages of 40 and 120 days prenatal and 30 day postnatal (four fetuses, lamb for each group), then used Routine histological stain haematoxyline and Eosin stain (H&E). Result show the juxtaglomerular apparatus development in the current study appeared in the Microscopic examination of kidney samples at 40 day age the juxtaglomerular apparatus was not developed in first trimesters of gestation in renal corpuscles and the embryo at 120 day age show The juxtaglomerular apparatus evolution became clear and relatively complete that consists of macula densa cells as row of cell in position in distal tubules and juxtaglomerular cells become clear and large nuclei and the lacis cell (mesangial cells) become more prominent in renal corpuscle that formed firstly histological. While the juxtaglomerular apparatus at 30 days postnatal of sheep it Very clear histological differentiation with higher cells that content elongated nuclei of macula densa cells, The presence of more mature juxtaglomerular cells near the entrance of the glomerulus was noted.