The previously proposed and tested bicultural self theory (Lu, 2007a; Lu & Yang, 2006) was further extended to mainland Chinese in the People’s Republic of China, and potential subcultural differences across the Chinese strait were explored. Results indicated that mainland Chinese generally endorsed various aspects of the individual-oriented self more strongly, but the two groups across the strait were not different in their overall endorsement of the social-oriented self. As social orientation is rooted in traditional Chinese conceptualization of the self and the individual orientation is brought in with modern Western influences, this pattern of differentiation was understood in the context of both common heritage and differing phases of societal modernization in mainland China and Taiwan. In addition, a brief version (24 items) of the “Individual- and Social-oriented Self” scale (ISS; Lu, 2007a, 2007b) was successfully constructed, and its reliability and validity mirrored its original full version of 40 items.