Building the behavioral model for each analog circuit is an efficient approach for mixed-signal system verification. If an automatic model generator is available, it is useful for designers to reduce the extra efforts. Instead of modeling the relationship between circuit inputs and outputs directly, a divide and conquer approach is proposed in  to divide the circuit into several small building blocks and model the behavior of each block easily. Although the regression efforts have been greatly alleviated in this structure-based approach, the preparation of the training patterns is still a big issue. In this work, a different approach is proposed to build the behavioral model of each internal block in structure-based approach without regression. Therefore, no training patterns are required in the calibration process. As shown in the experimental results, the model accuracy is still kept in the proposed approach while the efficiency of behavioral model generator is greatly improved.