With the deepening of research of domestic and foreign scholars, multilingualism research has also aroused the interests of scholars. This paper focuses on the diverse multilingual families in HK, which is a cultural blending classic. With a brief account of the language acquisition barriers among toddlers fostered under multilingual circumstances, this paper also analyze the causes of such phenomena. It ends with some advice on how to treat the toddlers’ language acquisition barriers in multilingual families and suggests that an evolutionary view on multilingual performance.