In this paper, we propose a new low-jitter transmission code for 4-PAM signaling in serial links. It is "8B/10B like code" which preserves all good properties of the 8B/10B code, such as DC balanced of the serial data and guaranteed enough transitions in the symbol stream for clock recovery. Further, it is effective to reduce the jitter of timing recovery and consumes half the bandwidth to transmit in 4-PAM. The design results using TSMC 0.25μm process shows that it can reduce the jitter of the transition time by ± 25%. The operation speed of the 8B/10B like encoder / decoder is 500 MHz with 16-bit inputs (8 Gbps) and 476 MHz with 16-bit outputs (7.6 Gbps).