This paper discusses the basic principles of high frequency reconstruction based on spectral bandwidth replication ( SBR ) technology. The implementation of an AAC decoder with SBR is presented in this paper. Some evaluation results of the implementation show its efficiency of audio decoding. 本文论述了高频重建技术的原理,并采用SBR技术,实现了AAC音频编码的高频重建,同时性能评测结果表明所实现的AAC+SBR系统满足实际应用的要求。