MOCVD growth and characterization of GaSb-rich and InAs-rich GaInAsSb on GaSb substrates was investigated. The surface of InAs-rich GaInAsSb epilayers showed morphological features very different from those on GaSb-rich films. Solid compositions of Ga1−xInxAsySb1−y films were dependent on growth temperature and the input source ratios, such as Ga/III ratio and Sb/V ratio. Unintentionally doped InAs-rich GaInAsSb showed n-type conduction, and GaSb-rich samples were p-type. A room temperature electron mobility of 5000 cm2v-1s-1 with electron concentration of 3.6×1017cm−3 for InAs-rich films was obtained. On the other hand, a hole mobility of 360 cm2v−1s−1 with a hole concentration of 1 × 1017cm−3 for GaSb-rich samples was achieved.