In this paper, we design an improved hard-decision quantization (HDQ) scheme for HEVC compression. A decision tree model is generated based on the behavior of the soft-decision quantization (SDQ) in HEVC, and it is utilized to help making decision for each quantized level in the proposed HDQ. Experimental results show that our proposed quantization scheme achieves an average of 3.11% coding gain compared to the conventional HDQ and it provides a more hardware friendly implementation than SDQ.