In this paper, we propose a new Channel-Adaptive Early Termination (CAET) strategy to early stop Low-Density Parity-Check (LDPC) decoders. Our method checks the sign-changing rate of the log-likelihood ratios, and is able to perform the early termination under all SNR ranges with simple methodology. The average decoding latency can be decreased from the preset number of 8 to 6.73 iterations with negligible performance degradation. In addition, we create the BER Performance Loss Ratio (BPLR) index to evaluate the performance loss of different ET criteria. Compared to the Hard-Decision-Aided criterion, our CAET strategy reduces the decoding iterations effectively and improves the BPLR by 76.6%.