To meet the high reliability of structural design and safety evaluation on carbon fiber wound reinforced polymeric (CFWRP) pressure vessel, the traditional safety factor design was substituted by reliability design based on the reliability theory and statistical principle. Eight CFWRP pressure vessels were manufactured with the same material system by the same winding technique. And experiments were conducted to obtain the probabilistic distributions of design variables. Results derived from reliability design (fiber thickness) agreed well with experimental results and were much lower than that from conventional design. Through comparison among reliability design results with different statistics of fiber strength, significant effect of the variation of fiber strength on structural reliability of composite pressure vessel was demonstrated. The conventional design was verified to be not reasonable since it considers only the mean value of fiber strength without the effect of fiber strength distribution on structural resistance of pressure vessel.