Valuation of global ecosystem services by R. Costanza (1997) has attracted attention of the Chinese ecological researchers over the years. Many Chinese scientists have been using the methods to valuate the ecosystem services for forest, grassland and farmland ecosystems. However, it has been turned out that there are several shortcomings in direct adaptation of the methods, for instance, some ecosystem services have been insufficiently valuated or even ignored. To meet this gap, we have used a “unit value” based method for assessment of ecosystem services. Expert interviews with structured questionnaire have been contacted in 2002 and 2007 respectively; altogether 700 Chinese ecologists have been involved in the interviews. It has been found that the values of ecosystem services from expert knowledge based unit value method and biomass based method are comparative. Therefore, expert knowledge based assessment of ecosystem services could be used as a method for the assessment with known land use areas, and a good result could be generated within a short time period. However, for scientifically sound and concrete results, a long term simulation of ecosystem service flux curve via experimental research is required, and spatial and temporal disparity of ecosystem services should be taken into account.