We study the interactions between foreign investors and the trading behavior, stock returns, and return volatility on the Taiwan stock market around the Asian Financial Crisis. The period is characterized as having high return volatility and severe information asymmetry. If the foreign investors do have private information, they are more likely to influence or lead the market during this period. It is found that foreign investors are positive feedback trading both before and after the Asian Financial Crisis. They tend to buy after the market increases and to sell after the market decreases. However, it is not closely related between today's order imbalance and next day's price increase or decrease. Meanwhile, there is mean reversion for stock return and return volatility after foreign investors' large order imbalance. Thus, the trading of foreign investors does not seem to contain private information and the impact of it on return volatility is minor.