Abstract: The quality prevention strategy of the famer specialized cooperatives was studied in the model of agriculture-super docking. The quality decision of the famer specialized cooperatives will be compared in the case of information symmetry and information asymmetry. The study was focused on the quality decision of the famer specialized cooperatives under the asymmetric information. The optimal solution of quality decision was obtained by the optimal control theory and Lagrange conditional extreme value under the asymmetric information. The results show that the more profit the famer specialized cooperatives generate by selling shoddy, the smaller amount of the quality prevention will be. In that case, the famer specialized cooperatives are easier to produce speculative psychology of selling shoddy. Under the asymmetric information situation, because the evaluating standard of supermarket is unobservable, the quality prevention costs of the famer specialized cooperatives will increase, the quality revenue of the famer specialized cooperatives will reduce.