CdGeAs2 polycrystalline was synthesized by temperature oscillation method, and an integral and crack-free CdGeAs2 single crystal with size of 28 mm×65 mm was grown by the modified vertical Bridgman method. The synthesized polycrystalline was characterized by X-ray diffraction (XRD). The CdGeAs2 wafer cut with a diamond cylindrical cutter was characterized by energy dispersive spectrometer (EDS) and IR Prestige-21 spectrophotometer. The results show that the synthesized product is CdGeAs2 polycrystalline with tetragonal chalcopyrite structure, and the atomic percentage of the wafer is close to the ideal stoichiometric ratio. The absorption coefficient of the as-grown CdGeAs2 crystal at 11.3 μm is 0.117 cm-1 and the fitted band gap is 0.52 eV. Temperature dependent (110 K to 300 K) Hall measurement shows that the sample is p-type conductive in the temperature range from 110 K to 300 K. The carrier concentration pH increases and the Hall coefficient RH decreases respectively with the increase of temperature, while the Hall mobility μH is almost unchanged. Fitting and calculating results show that the acceptor ionization energy EA is 0.305 eV in the crystal, and the possible acceptor defects in CdGeAs2 single crystal was further analyzed.