Platform managers should consider the effects of two-sided network externalities when make pricing decisions for users on both sides． Besides，investment strategies are also essential to platforms． Focusing on the online video platforms，a game model is developed to investigate the trade-off between the strategies of two-sided pricing and the investment of UGC ( user-generated content) ． Different video contents exhibit different attributes． The UGC attracts advertisers differently compared with the copyright contents，as affects the investment strategy of the platform． The platforms’joint-decision on pricing and UGC investment is studied． Three scenarios are considered: monopoly，duopoly with multi-homing advertisers，and duopoly with single-homing advertisers． Optimal decisions on two-sided pricing and UGC investment for each scenario are given，and are compared with those of traditional markets to explore the differences in terms of the decision-making． The results show how the platforms’investment and pricing strategies are affected by the characteristics of UGC and by the differentiation between competing platforms．