An efficient sign coding for transform skip mode is proposed in this contribution. It is observed that the signs of coefficients in the transform skip block have high correlation each other than those of transformed coefficients. Therefore, it is proposed to have a flag that indicates whether all of the signs in the current block are identical or not, before the signs of each coefficient are coded. The proposed method has BD-bitrate changes, 0.00%, 0.00%, 0.04%, for AI, RA, and LDB, respectively. Especially, it is observed that the proposed scheme has -0.30% and -0.81% of bit savings in Class F and Class SCC in all intra configuration, respectively.