Abstract: Magma intrusion in a sedimentary basin can lead to the change of the geothermal history of the basin, accelerate the maturation of the organic matters and influence the generation and preservation of oil and gas. Considering the fundamental physical properties of magma intrusion and the latent heat effect in magmatic cooling, the functional relation about the change in temperature site is established, the thermal evolution modeling of magma intrusion with VB program is finished, expounding the distribution, changed rule and influential factors of the temperature within the magmatic cooling as well as effect of magma intrusion on oil-generating window using timetemperature index (ITT). The modeling results indicate that: The magmatic cooling history can be divided into fast cooling stage and slow cooling stage. In the first stage, the magma intrusive body cools rapidly while the enclosing bed is heated simultaneously, followed by the temperature of magma intrusive body being closed to that of enclosing bed. In the second stage, the temperature of the magma intrusive body is close to that of enclosing bed, and it cools slowly. Magma intrusion can accelerate hydrocarbon maturation and shoal the depth of oil-generating window.

Key words: sedimentary basin, magma, intrusive body, modeling, oil-generating window