Rhesus monkeys (Macaca mulatta) are human's closest evolutionary relatives next to Chimpanzees, and they are widely used in biomedical researches. Analyses of the rhesus monkey trasnscriptome and the sequence divergence between monkey and human are of importantce to the development of scientific analyses and to the application and interpretation of the results from animal experiments. In this study, we analyzed the genetic and transcriptional information. Four hundred and one clones were randomly selected from a liver tissue cDNA library of rhesus monkey, and the expressed sequence tags (ESTs) were sequenced. We acquired 393 effective ESTs that were assembled into 221 Unigenes with Phrap software. Alignments of the sequences showed that 188 Unigenes matched with known proteins in Swiss_prot database, of which 16 Unigenes matched the known rhesus proteins, and 171 Unigenes had high homology with human proteins. Then the result of BLASTN comparison showed that 26 of another 33 Unigenes matched the known rhesus genes. Finally, the remaining Unigenes were aligned in dbEST and rhesus genome database, and the results suggested 3 Unigenes be newly discovered ESTs of rhesus.