The structure and source of PHS' market value was analyzed by traditional project value evaluation.  Real option method was used to reevaluate the PHS market value in consideration of the 3G license in the future.  It is concluded that although the PHS could not help the Fixed Phone Operators (FPOs) to gain the investment return in the short term, it still could help to acquire the 3G license of mobile phone and bring stable income in the long run,  o indicating that the essence that an enterprise is an economic entity.  When enterprise's interest is conflict with social interest, FPOs would, without seeing the risk of sacrificing industry development, prefer the technology-backward PHS in order to acquire its own profit.