This research aims to investigate whether information risk and liquidity become yield spread determinants of Indonesian corporate bond market. This study uses market microstructure approach. Previous research had revealed the impact of Volatility Model or the information effect on transaction (Balduzi et al., 1999; Brandt & Kavajecz, 2004; Green, 2004) and the sequential trade models used by Easley et al. (2002). In this research, information risk is measured by Probability of Informed Trading (PIN) model, liquidity is measured using Lesmond-Ogden-Trzcinka (LOT) model, and the Pastor and Stambaugh model is used to measure systematic liquidity risk. Using intraday transaction data of Indonesian corporate bonds during 2006-2011, all three main variables were found to influence Indonesian corporate bond yield spread. The average PIN of Indonesian corporate bonds is 7.98%, which is lower than that of the US market. The average LOT for the Indonesian corporate bond is 310 bps, which is less than that of the US market, and investor demand of illiquid bonds is more sensitive to systematic liquidity than liquid bonds.