Abstract: The non-linearity of I/O signals and multiple-input-switching effects bring serious challenges to timing analysis.To alleviate these problems,the Miller capacitance between input and internal nodes of gate cells are verified by designed circuit and device structure is analyzed to clarify its source.An Advanced Multiple-Input-Switching Current Source Model with higher accuracy is developed by introducing such capacitance and the proposed modeling method is extended to handle multiple-input gates.Numerical experimental results for various gate cells demonstrated that the proposed model significantly improves the simulation accuracy for delays and waveforms compared with the existing ones.