In the High Efficiency Video Coding (HEVC) based 3D video coding, 3D-HEVC, the disparity vector (DV) derivation is critical for inter-view motion prediction, inter-view residual prediction, disparity-compensated prediction (DCP) or any other tools exploiting inter-view correlation. In HTM-5.0.1, the DV is derived from some spatial and temporal neighbors to locate a corresponding block in another view. This paper advocates modifications of the DV derivation to reduce the complexity and to achieve slightly better coding efficiency. Firstly, we propose to remove the additional temporal block, unify the DV searching order for all views, and to impose restrictions on the temporal blocks for memory access bandwidth and complexity reduction in DV derivation. We also propose an improved DV searching order for slightly better coding performance. These proposed methods were adopted into the 3D-HEVC standard in the 3rd JCT-3V meeting in Jan. 2013.