Abstract:It seems a highly-cited view that lottery contracts have dual attributes of sales contracts and aleatory contracts .Nonetheless,to put this standpoint as a prevailing qualitative theory of lottery contracts,there still remains three bones of contention : First,the establishment of lottery contracts focuses on the consensuses between the parties to a contract,and it also lays emphasis on the clean and effective executions and deliveries of lottery tickets .Thus,lottery contracts are typical real contracts .Second,lottery contracts do not share the same essence as ordinary contracts for sales,in spite of such external forms as″purchase″and″sale″in legislation,keeping in line with international practice,the phrase″prize winning donation″may be in better accord with the interests of lottery issuance and public welfare in China .Third,lottery contracts,as aleatory contracts,are similar in tool,to those for gamble,but in value,lottery tickets are franchised and issued by the state for the purpose of raising public welfare funds and promoting the development of public welfare establishments in China .Therefore,their legitimacy value originates from the purpose of public welfare behind lottery contracts . As far as the contracts for donation are concerned,they should go back to real contracts under specific conditions(e .g .,small amount of donations about which their recipients remain unclear),for the above-mentioned purpose of public welfare .The traditional opinion,arguing lottery contracts were donation contracts subjected to collateral obligations,was widely criticized for its excessive simplicity and indistinctness . In fact,lottery contracts,as prize winning donation contracts,according to the principles of lottery funds' expenditures and revenues managed separately,can be interpreted as dual models of contracts .The first is typical standard form of the-general-public oriented donation contracts .These contracts are established when the two parties concerned reach the consensuses about donation,and when the donator pays the money equal to the fixed face value of lottery tickets .Donation contracts are irrevocable because of their natures serving public interests or fulfilling moral obligations,such as disaster or poverty relief,etc .The second is that,for the lottery holders' part,donation contracts are bound with aleatory dissolving condition,namely,″not winning after drawing lottery .″With the consensuses about donation issues between lottery issuers and lottery buyers,the contracts are established by deliveries of clean and complete lottery tickets,which are irrevocable on account of notarization . The theory of dual models of donation contracts helps to solve effectively in sales contracts theory the three difficult problems of lottery buyers' supervisions over lottery public welfare fund,lottery prizes paid to juveniles,and identification and attributions of abandoned lottery prize .From the perspective of dual models of donation contracts theory,lottery tickets are vouchers which certify establishments of dual donation contracts,as well as,negotiable securities with which lottery buyers are allowed to claim for the prize money .The expectant rights created and indicated by lottery tickets will be attributed to elimination in case of no prize and otherwise translated into actual obligatory rights . The theory of dual models of donation contracts contributes significant value in practice .It can guarantee system interests and social public interests of the issuance management of lottery tickets,prevent and control moral hazards and other negative external factors of the issuance management of lottery tickets,create simple and highly efficient litigation channels between lottery buyers and lottery sellers,and finally,promote the lottery system development with better regulation and order under the market mechanism .