Chronic Obstructive Pulmonary Disease(C.o.p.d)is Characterized by Airflow Limitation Leading to Reduced Ventilatory Capacity and Is Associate With Shortness of Breath.c.o.p.d Have Become Increasingly Important Cause of Morbidity and Mortality in Modern World. Objective of Study Is to Assess the Effect of Pulmonary Rehabilitation on Exercise Tolerance and Health Related Quality of Life in C.o.p.d Patients. This Study Carried Randomly Selected Patients and They Are Divided Into Two Groups Experimental and Control Group.the Experimental Group Underwent Two Months Pulmonary Rehabilitation Program in Addition to Medications and Control Group Patients Using Medication Only.experimental Group Shows Significant Improvement in Exercise Tolerance and Quality of Life.