Ayurveda is a science which deals with life, where advantageous & disadvantageous as well as happy & unhappy state of life along with good & bad for life, its measurement & description of life itself is explained. Life span (Ayu) is continuation of consciousness; it is the act of keeping alive, Ayu is combination of body, sense organs, mind & soul. The objectives are to maintain the health of healthy individual & to cure the diseases of patient.To fulfill the objectives of Ayurved, various samhitas are composed, which deals with anatomy, physiology, diagnosis of diseases and its treatment. The samhitas which have gain importance are Brihattrayee and Laghutrayee. This paper discusses about the description of „Atisthaulaya‟ in Brihattrayee.