In this paper, my topic is related to the cognitive identity case in Hong Kong. To research this topic, the Chinese diaspora in Southeast Asia will also be discussed and compared to illustrate what factors may caused the case occurred in Hong Kong. The topic of this paper will be discussed in terms of historical development, with this comparison, I will explain how the historical development of cognitive identity in Hong Kong from the colonial era to the present. Meanwhile, unlike the case of Hong Kong which is disappearing their cognitive identity which is national identity in China, there are Chinese diaspora in Southeast Asia who still consider themselves as the successors of Chinese culture. With this comparison, I want to find a solution to avoid cases like this that occur in Hong Kong so that the cognitive problem of identity of people who has followed the Hong Kong case will also be changed and also truly be considered their identity as Chinese citizen. To research this topic, I will use the literature review method.