CdTe- and Eu3+-doped CdTe quantum dot (QD)-sensitized TiO2 nanotube array (TiO2 NTA) photoelectrodes were prepared by using one-step aqueous synthesis. The effects of Eu3+ doping concentrations on the properties of CdTe QDs and CdTe/TiO2 NATs were systematically investigated. The absorption band of the sensitized TiO2 NTAs red shifted and broadened to the visible region when the CdTe- and Eu3+-doped CdTe QDs were deposited. The maximum incident photon of the current conversion efficiency (IPCE) value was 19.5% at 320 nm when the Eu3+ doping concentration was 2%. The photoconversion efficiency of CdTe:2% Eu3+/TiO2 NTAs increased to 1.09%, which was 28 times and 78 times that of CdTe/TiO2 NTAs and pure TiO2 NTAs, respectively. These results indicated the potential application of the prepared photoelectrode in QDs-sensitized solar cells (QDSSCs) and provided a basis for the development of QDSSCs.