This study examines the effect of corporate ownership on information asymmetry as measured by bid-ask spread in the emerging markets of China. Government ownership has significant and positive impacts on bid-ask spread during the period 1995-2000, but disappears afterward during 2001-2003. The finding that state ownership raised bid-ask spread in the early period is consistent with recent studies on emerging markets including China, which indicate that firms with higher state ownership tend to have a greater deviation between cash flow rights and control rights(eg, Wei et al., 2005). This implies that lower state ownership is associated with lower information asymmetry in the market, an economic consequence of significant economic reform and privatization regarding the market microstructure. However, with more active control transfers andemergence of private controlling shareholders, regulatory changes in ownership structure and corporate governance mechanisms, and thus an improved legal and institutional environment, the link between the government ownership and information asymmetry turns to be insignificant in the later period. These results have important implications for transparency and information disclosure policies as well as privatization in emerging markets. This study examines the effect of corporate ownership on information asymmetry as measured by bid-ask spread in the emerging markets of China. Government ownership has significant and positive impacts on bid-ask spread during the period 1995-2000, but disappears afterward during 2001- 2003. The finding that state ownership raised bid-ask spread in the early period is consistent with recent studies on emerging markets including China, which indicate that firms with higher state ownership tend to have greater deviation between cash flow rights and control rights (eg , Wei et al., 2005). This implies that lower state ownership is associated with lower information asymmetry in the market, an economic consequence of significant economic reform and privatization regarding the market microstructure. However, with more active control transfers andemergence of privately-controlled shareholders, regulatory changes in ownership structure and corporate governance mechanisms, and thus an improved leg al and institutional environment, the link between the government ownership and information asymmetry turns to be insignificant in the later period. These results have important implications for the transparency and information disclosure policies as well as privatization in emerging markets.