Largescale and highprecision aerogeophysical survey provides reliable data for lithologic classification, and BP neutral net supplies effective means to lithologic classification. Based on the principle of BP neutral net model, the authors compiled the BP neutral net software for the processing and interpretation of aerogeophysical data and successfully used this software to the lithologic classification and interpretation of airborne gammaray spectra. Practical examples show that the application of the BP neutral net method to the processing and interpretation of such aerogeophysical data classification problems as lithologic division has very obvious effects.