Social media has become a popular marketing way for all sizes business to close to their prospects and customers. Event marketing is important to get event information from the target market and create awareness. Great social media marketing can bring dramatic success to event organisation. Hamilton Chinese Students Association (HCSA) is a young organisation, which provides events for Chinese students. As an event organizer, HCSA has already kept a series of right communication tools for its members and target audience. However, the social media marketing plan is still waiting to improve. Thus, the aim of this research is using HCSA's event as a case study to analyse the use of social media in event marketing and provide recommendations. A combination of quantitative research and qualitative research has been used in this research. Event marketing theories and social media marketing tips have been analysed with HCSA's practices. The staff and target customer of HCSA have participated in the data collection process. With data analysis, several recommendations are given to help HCSA build up an effective event social media marketing plan.