Abstract：Aimed at two complex surface conditions of Shengli oilfield in 1998一1999 and through researching surface feature of special complex region，the paper proposed a construction method of variable geometry.On design of 3-D seismic prospecting geometry，the attributions of bin are selected by geological objects. It contains two key elements:offset and azimuth. Different geometry has its respective offset and azimuth，both of them are determined by folds (vertical folds affect on offset distribution and lateral folds affect on azimuth distribution);therefore，we discussed on both vertical and lateral folds of geometry. Correlation analysis both on attribution of bin before and after variable geometry in theory and on reasonableness of variable geometry adopted in these regions have been constructed，the difficult problems in field construction have been solved and fulfillment of geological task has been guaranteed.
