The relationship between Heritage Language (HL) and ethnic identity has gained significant research ground in social psychological and poststructural scholarship, with empirical evidence largely emerging from the North American settings. There is little pertinent sociological work conducted outside North America. To fill this gap, this sociological study sets its scene in an Australian context. Drawing on Bourdieu's notion of habitus, the study examines the contribution of Chinese Australians' Chineseness to their Chinese Heritage Language (CHL) proficiency. A total of 230 young Chinese Australians completed the online survey. Results from multiple regression indicate that habitus of Chineseness is one of the significant predictors for the CHL proficiency of these young people. The study makes a theoretical contribution to investigate ethnic identity-HL link through the notion of habitus and makes a methodological contribution to quantify this habitus.