A bicycle saddle assembly comprises a saddle body including a wider posterior portion for supporting bicycle rider's buttocks and a narrow anterior portion which fits between bicycle rider's crotch. The saddle body further includes a concave portion provided between the wider posterior portion and the narrow anterior portion. The saddle body has a highest area located on the wider posterior portion and a lowest area located on the concave portion to define an opening space with a sufficient depth above the concave portion so that, as riding, bicycle riders can arrange his perineal areas comfortably on the saddle body to relieve pressure placed thereon and dissipate heat generated therein.