Abstract: To analyze the complicated structural system reliability,based on classical PNET method and response surface method,an advanced PNET method is presented in this paper.The system reliability of a ten-floors steel frame structure is analyzed using the advanced PNET method.Results show that exact results can be abtained using high order term advanced PNET method,and the calculation time is shorter than using Monte Carlo method.The new method effectively reflects the correlation between failure modes of the structure and system,and better reflects the structure performance.