Abstract: Bsaed on hydraulic treatment mechanics and geologic characters of carbonate fractured reservoirs，this paper considers" carbonates-earth movement stress-natural fluid-frac-tured fissure-trap"as a system,and studies the initiation of the fractured fissure and the first migration of oil and gas,the stretch and expansion of the fractured fissures and the sec-uond migration of oil and gas，the shape distributions of the fractured fiss res. and accumula-lion laws of oil and gas systematically，and thus builds up the mechanism of natural fluid fractured reservoirs. It has high theoretical meaning and applicable value in the exploration and development of fractured reservoirs.

Key words: Carbonate Stress analysis Fluid dynamics Fract