Based on the analysis of the formation of ecointerest, the connotation of ecointerest compensations is defined, the reason for ecointerest loss is analyzed by the theory of truncation of property rights, that the essence for ecointerest loss lies in truncation of property rights is put forward, as a result, the necessity for ecointerest compensation is analyzed from the perspective of the interaction between ecointerest fairness and efficiency. On the basis of this, the principle, capital source, ways and security mechanism for ecointerest compensation are advanced so that the implementing mechanism for ecointerest compensation is studied. Ecointerest public compensation by taking governments as the agents is the effective solution to the contradiction between the fairness and the efficiency of ecocompensation.