In foreign economics experiments, public goods game experiments are mainly used to analyze the cooperation issue in two social dilemmas. Research finds that there are different kinds of subjects in public goods experiments, among which conditional cooperators are most common types, the use of monetary penalty can maintain higher cooperation level, but the penalty itself produces public goods problems with the second-order level, the efficiency hidden in monetary penalty is not significant, however, social penalty may not increase cooperation but decrease efficiency, and non-monetary penalty, such as the persons expressing dissatisfaction, expelling free riders and so on, and non-penalty mechanism, such as communication, intergeneration advice and so on, can also maintain higher cooperation level and efficiency. These experiment evidences are of important enlightenment role in constructing harmonious society in China, especially how to apply the experience of economic experiments to“practical”environment to make institutional design for solving the two dilemmas, which is important direction for further study. 