Since the 20th century, foreign library policy evaluation model has gone through four stages:tooloriented measurement evaluation, goaloriented description evaluation, decisionoriented assessment evaluation and valueoriented construction evaluation. The paradigm of library policy evaluation translates from empirical demonstration to theoretical construction, suggests the changes of assessment orientation from control to participation, learning from the development history of foreign library policy evaluation models, it is found that constructing theories of library policy evaluation in China should be realized by going beyond positivism paradigm，highlighting social construction wisdom, breaking the onedimensional position between the policy makers and evaluators, and establishing stakeholder orientated system.