The upgrading trend of CATV network is from traditional HFC networks to a two-way system.But there is a problem of the inefficiency of experienced engineers who design the passive coax distribution networks of HFC.Intelligent evolutional algorithms are applied to design passive coax networks

including Genetic Algorithm(GA) and Estimation of Distribution Algorithm(EDA).The model described is based on the tower building structure.The results show that the method could converge fast and give out a desired result of the parameter selection

which makes up the drawbacks of the existing design software that can not properly applied in the Chinese building structure.It lightens the dependence on the designer's experience as well as meets the engineering requirement.