Wavelet extracting is the essential technique of impedance inversion.A wavelet is generally extracted based on the assumption of normal incidence by the deconvolution of reflectivities obtained from well log with a seismic trace near the well.But actural seismic waves do not always strike a interface normally

and the reflectivities change with offset.Therefore

there must be considerable differences between the reflectivities obtained and the real ones.In this case

a newly derived recursion formula for calculating reflection coefficient by slope incidence is proposed in this paper

and it could improve the acuracy of wavelet extracting and impedance inversion and seismic interpretation.The result of model calcultion has proved that the accuracy of wavelet extracting and the result of deconvolution have been improved.