Abstract: According to the financial market microstructure theory, this paper uses bid-ask spread of bilateral quotes to measure the treasury bond liquidity, and conducts an empirical study on the weekly patterns of the Interbank Bond Market liquidity and determinants that affect treasury bond liquidity. The empirical study finds that there is no significant difference among the treasury market liquidity at different time. In addition, the factors that affect the treasury bond liquidity include trade size, transaction price, risk( volatility of quotes), maturity and issue size.