Abstract: The study on investment rules of oil and gas development and the predictive analysis on investment demand are main contents for development strategy making and planning for petroleum enterprises. The newly?established oil and gas productivity, development work capacity and cost, investment and benefit variations during 2001-2010 in Junggar basin and its individual petroliferous zone are compared and analyzed, based on which the quantitative estimation of the future oil and gas development investment is made with mathematical prediction methods. It is suggested that the oil development investment benefit of the basin during“the Eleventh Five ?Year Plan”period shows a generally declining trend compared with“the Tenth Five?Year Plan”period. This is mainly because of the decrease of large?scaled and high?quality reserves, low level of producing reserves and the continuously increasing difficulties of newly?established productivity.Generally, the development benefit in northwestern margin of Junggar basin is relatively good, and the development benefit of heavy oil is higher than that of thin oil. With the increase of newly?established productivity during“the Twelfth Five?Year Plan”period, the development investment exhibits a rising trend. It is proposed that the high?quality oil and gas resources development investment should be further increased and the application of new technologies should be highlighted to guarantee the steady growth of oil and gas production and the improvement of development benefit in Junggar basin