User-generated content is the content created by users on Internet platforms such as social media, e-commerce websites, video-sharing websites, which has the forms of text, image, audio, video and so on. User-generated content is crucial to the orientation of platforms, the survey of enterprises and the choice of consumers, but its shortage and under-contribution are major problems on many platforms, which are related to its inherent attributes of public goods and users’ fatigue effects. In order to encourage users to generate content, a variety of incentive systems are adopted, and the effect of which has become a hot research topic in recent years. Given that study on this issue is new and largely fragmented, it will be theoretically important to understand what has been studied. In this study, we conduct a systematic review of related literature. For one thing, we discuss the concept and classification of user-generated content from multiple angles , and compare them with electronic word of mouth, value creating and so on; then we classify incentive systems into the economic type, the non-economic type and their combination. More importantly, we evaluate the advantages and disadvantages of various incentive systems and sum up the influencing factors of their effects. Various incentive systems take advantage of different user motivations, so we also analyze them. Economic incentives include offering monetary rewards, discounts and coupons, other user donations and so on. This type of incentive plays a role in stimulating all users to generate content in the short term, but it is not feasible in the long run, especially for active users. It even has a negative impact on the content quality. Non-economic motivation systems have more forms, commonly including gamification designs, reputation visualization and providing norms. Points system, ranking system and peer-rating system are essential elements in the gamification solution, which can inspire users to contribute more information in general, especially at the period of approaching certain level, taking advantage of their motivation of pursuing honors, external rewards, attentions and so on. However, the effect of the points system incentive is periodic. After achieving the fixed target, users’ contribution frequency reduces significantly, and with the users’ level increasing, the average quality of content declines. Reputation visualization contains displaying data associated with users or content, for instance, the shared number, contributors’ personal information, etc. Research results show that this kind of motivation can positively affect the users’ contribution behavior for a long time, and when reviewers’ personal information is disclosed, their comments are more positive, but for users pursuing reputation, the frequency of creating content decreases as the content can not affect the number of followers. Providing social norms can also be a positive stimulus, but external standards have no effect on the inactive users. The combination of economic incentives and non-economic incentives can be conducted simultaneously or in different stages, which can avoid the corrosive effect of money for active users. Future studies can consider giving users a large number of economic rewards, introducing punishment mechanisms and joint incentives of multiple platforms. By providing a systematic review of different incentive methods and their benefits and shortcomings, we believe that we will contribute to the understanding of the UGC incentive systems, give a useful basis for UGC research, and help enterprises or platforms to make appropriate incentive policies in the future.