This paper considers informed traders’ trading strategies in a bear market. Known as stealth trading, one strategy of informed traders’ is to use medium-size trades, which tend to contain more information than small- and large-size ones and thus to have stronger impact on stock price movement. Using the tick-by-tick data of Shanghai 180 Index Component Stocks, we document the strong pattern of stealth trading in Chinese stock market during the period of June 1, 2004 to May 31, 2005, which is: (1) an order-driven market; (2) a market that has limit orders only; (3) a bear market; (4) a market with no corresponding derivative market; (5) a market with short-selling constraints; (6) an emerging market. The results extend the empirical evidence on the stealth trading by documenting the fact that price movements are mainly due to the medium-size trades. We find that the pattern in a bear market is highly consistent with that in a bull market. First, we observe that the per-transaction stock price changes in different trade-size categories exhibit a clear U-shape and only the price changes induced by medium-size trades are consistent with the market movement direction. We formally test the stealth trading as well as four alternative hypotheses, and conclude that stealth trading hypothesis can correctly explain this phenomenon. Second, the evidence shows that the medium- size trades have stronger impacts on price change s in the stocks whose price movements are highly consistent with the market (in our study, it refers to those stocks with severely low cumulative return in the sample period). Third, we further document that there is strong interaction between stealth trading hypothesis and order imbalance hypothesis. However, after controlling the effect of order imbalance, the stealth trading hypothesis still holds, but the magnitude is much lower. It is suggested that the follow-up researchers take into consideration the effect of order imbalance, when confirming the existence or the magnitude of the stealth trading.