In this study, development of anther wall of Helianthus annuus L. male fertile HA 89 "B" line and cytoplasmic male sterile HA 89 "A" line were compared by light and electron microscopy. It was observed that there was no difference between male fertile HA 89 "B" line and male sterile HA 89 "A" line development of anther wall until tetrads were formed. After tetrad stage it was observed in male fertile HA 89 "B" line that the middle layer was lost, tapetum was parted from anther wall and it surrounded the microspores. In cytoplasmic male sterile HA 89 "A" line, middle layer was vacuolated and widened, tapetum also enlarged and it filled anther sac. It was determined that middle layer and tapetum were permanent with epidermis and endothecial cell during the further development of anther wall, and also there was no secondary thickening in endothecial cells. In conclusion it was found that the plasmodial tapetum which developed in fertile HA 89 "B" line transferred nutrients to microspores and helped them develop normally, but in cytoplasmic male sterile HA 89 "A" line the plasmodial structure did not develop. The inner tangential wall of the tapetum which was related with tetrads was not degenerated, sufficient nutrient were not transferred to microspores and thus they degenerated into the callose wall.