Abstract: In the aircraft design the safety factor / is a design limit load of struc-turs in the ultimate load of structure. It provides guarantee for certain degree of safety. In fact, from the reliability design point of view, both the strength and load are random variables obeying certain distributions. Therefore, the concept of simple safety factor of reliability fx is introduced. It concerns with coefficient of variation of normal distribution and reliability index and it only adopts to simple elements or a single failure mode of a structure. For composite laminates the concept of comprehensive reliability safety factor based on reliability analysis is presented and its rangs is given. Comprehensive reliability safety factor relates to the disperse degree of strength and load and the value of required reliability. Several failure modes of laminate, different load group and the effect of structural parameters of laminate are also considered. The application of comprehensive reliability safety factor is convenient as general safety factor and its characteristics is better than simple safety factor of reliability.

Key words: composite laminate, comprehensive reliability, safety factor