The failure rules of brittle rock under uniaxial compression test are studied primarily by using numerical simulation. The brittle rock failure mechanism and the end effect in the numerical simulation test of brittle rock failure are discussed; and some primary conclusions have been drawn. In the uniaxial compression test of brittle rock

tension failure dominates the failure process. Besides the material heterogeneity of rock specimen

the end effect is another important factor to affect the failure pattern of rock specimen. In general

such rules are in existence; the end restraint is more bigger

the failure pattern of rock specimen is more close to “X” dilatancy failure; the end restraint is more smaller

the failure pattern of rock specimen is more close to tension failure.