In High Efficiency Video Coding (HEVC), the coding efficiency of infra-frames is lower than inter-frames, which will cause the flicker artifact and perceptual fluctuation among CTUs in low bitrates applications. Therefore, this paper proposes a region-based intra-frame rate-control scheme to improve the objective quality and to reduce PSNR fluctuation among CTUs. Firstly, the CTUs in intra-frame are classified into three regions according to their characteristics and complexity. And a region-based bit allocation is proposed to pre-determine bit among different regions. Secondly, a rate-complexity-quality model is proposed for infra-frame to adjust the QPs to achieve a smooth perceptual quality. The experimental results demonstrate that the proposed scheme can achieve higher coding performance and consistent visual quality when compared with the scheme adopted by HM12.0.