ABSTRACT
More than three hundred vesicular glands of native Iranian bull in different ages were Collected. Their morphology, form, Position and relations to other organs were studied completely. Their weights and volumes were measured. Plastic solution of resin were injected through main excretory ducts of right and left glands and casts of ducts were produced. The vesicular glands are the largest of the accessory genital glands in the ruminants. They are paired and lies, cranial to the pelvic urethra. The glands were long and lobulated. Each glands have a long main excretory duct which is divided to several small branches in the lobules. The excretory duct joins the terminal part of the ampulla of ductus deferens. There were significant differences [P < 0.05] between aged groups in relation to length, width, weight and volumes. Glands of 4 to 5 years old bull have largest length and width. But glands of 10 years old bull have least dimentions. The symmetrical vesicular glands of the 4 to 5 years old bull have largest weight and volume. There were no significant, linear regression between means of length, width, weight and volumes of the glands by using student test