基因的编码区（英语：Coding region），亦称为“编码串行”（Coding sequence）或“CDS”（Coding DNA Sequence），是指DNA或RNA中由外显子组成，编码蛋白质的部分。该区域的边界范围从靠近5′末端的起始密码子开始，到靠近3′末端的终止密码子为止。mRNA的编码区范围位于5′非翻译区和部分同样为外显子的3′非翻译区之间。

某个生物体的编码区是指该生物由基因编码区组成的基因组的总和。

The coding region of a gene, also known as the coding sequence or CDS (from coding DNA sequence), is that portion of a gene's DNA or RNA, composed of exons, that codes for protein. The region is bounded nearer the 5' end by a start codon and nearer the 3' end with a stop codon. The coding region in mRNA is bounded by the five prime untranslated region (5'-UTR) and the three prime untranslated region (3'-UTR), which are also parts of the exons. The CDS is that portion of an mRNA transcript that is translated by a ribosome.