This study examines the practices of code-switching via virtual community WeChat and its impact on interpersonal relationships among young adults. It is worth mentioning that this study is based on my personal experiences and observations. As a Cantonese speaker from Zhuhai has stayed in Macao for two years, I was deeply influenced by the speech behaviors of local Macao people switching codes between Cantonese and English, so did my peers in the age group from 22 to 30. Code switching has been considered as a common feature in the discourse of people from Macao or Hong Kong, especially among the young people. It was until I came to Macao I fostered the habit of mixing between English and Cantonese. The changes occur without any notice, which echoes communication accommodation theory developed by Howard Giles. The change of speech by switching codes while conversing with others is a strategy to adapt to the local environment. At the age of 25, I am an active social media user. WeChat is one of the social media I used most and my peers as well. It is normal that offline speech behaviors are consistent with online speech by mixing codes. Texting online even enrich communicating codes in virtual communities. According to Gerry Philipsen‘s theory of speech codes, people will develop informal codes for communication and they are 3 readable by certain communities. That’s why in this study take WeChat as medium to explore its impact on communicating and relating to the young. In light of the geographical and cultural proximity between Macao and Zhuhai, these two places are the places of research. Based upon the lingua franca Cantonese, participants involved in data collection were mainly from Macao and Zhuhai and they all are my close friends. To some extent, it helps me more easily approach the target subjects to be studied. This study aims to see the impact of code switching on communicating and relating among young adults in Macao and Guangdong. Key words: code switching, WeChat, interpersonal relationships, personal experiences and observations, adapt, speech, Cantonese, Macao, Zhuhai, strategy, communities