The high-quality CdIn2S4 epilayers on the GaAs(1 0 0) substrate were first grown by using the Hot Wall Epitaxy Method. The grown CdIn2S4 epilayer was found to be the <1 1 0> direction. The optimum growth temperatures of the substrate and the source turned out to be 420degreesC and 630degreesC, respectively. From the measurement of the temperature dependence of the Hall mobility, the scattering at the high-temperature range was mainly related to the acoustic mode of lattice vibration and the scattering at the low-temperature range was most pronounced due to the impurity effect. The temperature dependence of the energy band gap on the CdIn2S4/GaAs epilayer obtained from the optical absorption measurement was found to be E-g(T) = 2.7116 eV -(7.65 x 10(-4) eV/K)T-2/(425 + T). (C) 2003 Elsevier B.V. All rights reserved.