We have detected molecular and atomic line emission from the hot and warm disks of two Class I sources , IRAS 03445+3242 and IRAS 04239+2436 using the high resolution Immersion GRating INfrared Spectrograph ( IGRINS ) . CO overtone band transitions and near-IR lines of Na I and Ca I , all in emission , trace the hot inner disk while CO rovibrational absorption spectra of the first overtone transition trace the warm gas within the inner few AU of the disk . The emission-line profiles for both sources show evidence for Keplerian disks . A thin Keplerian disk with power-law temperature and column density profiles with a projected rotational velocity of \sim 60–75 km s ^ { -1 } and a gas temperature of \sim 3500 K at the innermost annulus can reproduce the CO overtone band emission . Na I and Ca I emission lines also arise from this disk , but they show complicated line features possibly affected by photospheric absorption lines . Multi-epoch observations show asymmetric variations of the line profiles on one-year ( CO overtone bandhead and atomic lines for IRAS 03445+3242 ) or on one-day ( atomic lines for IRAS 04239+2436 ) time scales , implying non-axisymmetric features in disks . The narrow CO rovibrational absorption spectra ( v =0 \rightarrow 2 ) indicate that both warm ( > 150 K ) and cold ( \sim 20–30 K ) CO gas are present along the line of sight to the inner disk . This study demonstrates the power of IGRINS as a tool for studies of the sub-AU scale hot and AU-scale warm protoplanetary disks with its simultaneous coverage of the full H and K bands with high spectral resolution ( R = 45,000 ) allowing many aspects of the sources to be investigated at once .