Abstract: On basis of sedimentology,oil field geology,accompanying with drilling well,oil well test and experi mental data,the geological characteristics of complex oil and gas belt in Dawa-Haiwaihe area was analysed and their accumulation pattern was proposed.It was indicated that there were rich source rocks,well de veloped multiple set of reserviors,various traps in the area.Under structural and depositional controls,various hydrocarbon accumulations were widely developed and a complex oil and gas belt with different oil and gas reserviors was formed in the area.