This paper analyzes order aggressiveness in Shanghai stock market of China which is a pure order driven market. We provide empirical evidence that the mean order aggressiveness is negative （low） and most traders are liquidity providers. Our results also show that high order aggressiveness accompanied with high market volatility and large trade volume. The intraday order aggressiveness pattern is from low to high. Four factors： spread, volatility, order imbalance and size affect order aggressiveness, but they affect the buy and sell side differently.
