Abstract: The prediction of fracture pressure of formation is useful to carrying out fracturing technology. This paper discusses the determination of parameters of Ea-ton's equation which can calculate the gredient of fracture pressure of formation i.e. G_t = G_p+ [σ/ (1-σ)] (G_σ-G_P) . periicularly approching how to apply acoustic log to calculating Poisson's ratio σ. and experimental equation of dis- persed shale content in rock to it. Comparing the calculated value of fracture pressure of formation of well XL6 with its determined value, we found that their absolute error is only 0.2MPa. It shows that the result is believable. and the method is available. The calculation of gredient of fracture pressure of formation in wells X18 & X36 confirms the control function of fault or structure. and points out the changes of the gredient of fracture pressure of formation of each reservoir, which is controlled by Karamay — Wuerhe fault.