A modeling method of neuro-fuzzy system including a rule-defining process and a network-building process is disclosed. The rule-defining process divides a plurality of training data into a plurality of groups to accordingly define a plurality of fuzzy rules, and the network-building process constructs a fuzzy neural network based on the fuzzy rules obtained by the rule-defining process. The provided modeling method of neuro-fuzzy system is capable of building a neuro-fuzzy system extremely similar to an original function that generates training data of the neuro-fuzzy system.