Good oil and gas shows have been discovered in Eogene magmatic rocks in the southern slope of Huanghekou sag，but due to the large differences of magmatic rock distribution，complex lithology and strong heterogeneity，the signaltonoise ratio of seismic data is low and the seismic response is poor，bringing difficulties to favorable reservoir prediction.In order to solve the above problems，based on the system analysis of sidewall core and logging and seismic data，“threephase”coupling relationship between magmatic rock facies，well logging facies and seismic facies was established，which helps to describe the distribution characteristics of magmatic rocks by using variance and amplitude attributes and wave impedance inversion effectively. Based on the relationship among sensitive seismic attributes，inversion and magmatic rock lithology，the temporal and spatial evolution history of magmatic activity was defined，and the patterns of magma activity were established in different periods. According to sidewall core and outcrop data，the magmatic rock reservoir features and main controlling factors of reservoir were analyzed，which helps to use root mean square amplitude attribute and wave impedance inversion method to describe the favorable reservoir of magmatic rocks under the constraint of the ancient landform background，and the prediction result was proved by drilling.