With the rapid development of live streaming industry, live streaming firms try to increase performance by forming users’ payment habits through social network.  This paper collected the live streaming data of nearly 30, 000 users in an online music community.  Based on social presence theory, we tested the impact of the number of strong ties on user's gift-giving decision in user-generated live streaming.  Besides, we studied the moderating effect of audience scale, network centrality of tippers and levels of tipped broadcasters.  When a user engaged in a live streaming, the results show that, ( 1) the number of strong ties has a positive effect on tipping to friends； (2) the increase of the size of live streaming weakens the above effect； (3) when the user has a relatively higher social centrality, the main effect becomes lower； (4) The main effect is more pronounced when the levels of tipped broadcasters become higher.  Overall, this research has significant implications for firms' strategies to facilitate live streaming and achieve competitive advantages.