Abstract: In this paper, a probability and statistic equation for brittle fracture is proposed based on theconcept of individual cumulative fracture probability. It is related to thedefect density and the cumulative fracture probability, as well asthe stresses. Some previous fractureprobability and statistic equations are shown to be special cases of this equation andthe defect density and the cumulative fracture probability play animportant role. The number and the distribution of the fragmentsare obtained from the equation and the related probability and statistics.