Abstract: As a legally allowed monopoly or joint action, patent co-ownership arrangement should be a kind of legislation confirmation on the individual needs existing in our practical economics.But reviewed by the commonly used economic analytical means such as transaction cost and game theory, our patent co-ownership arrangements are surprisingly found under circumstances that it brings out a burden to the transaction cost of co-development, and that it may dilute the owner's interests or even corner the interests to marginal cost due to the tendency of abused license by its co-owners.Therefore, it is necessary to make further study and improvement on patent license and profit distribution arrangement to lower down the transaction cost, and to reach the target of effective source distribution and profit maximization.Meanwhile, it is necessary to limit the patent license among the co-owners under a certain agreement to avoid the tendency of tragedy of commons.