Abstract: A process parameters design system of resistance spot welding of aluminum alloys integrating case based reasoning,fuzzy inference and fuzzy neutral network(FNN) was developed.Material physical parameters such as electrical conductivity,yield strength etc.were used as inputs of the system.This more suitable to the physical mechanism of resistance spot welding process.It showed more flexibility to design process by using process intensity as one of the parameters.A FNN was built to improve the intelligence of solution to process design and its learning ability.The results of numerical simulation of resistance spot welding aluminum alloys were included in database as a complementary for the FNN training.It enriched the training samples of FNN and intensified generalization ability of the system.The applications approved that the system was able to meet the practical demand of the process design.