Abstract: We obtained 332 coding sequences from the Polyporus umbellatus transcriptome based on the BLASTx and ESTScan analyses. The codon usage patterns of P. umbellatus were calculated and statistically analyzed using CodonW. The results showed that the average GC content of genes was 53.57% and the average GC3 content was 57.98%, suggesting that genes favored codons ending with G or C. The effective number of codons (ENC) value range from 38.46 to 61, which indicates that these genes have low codon usage bias. The neutrality plot and ENC-plot analysis revealed that many factors such as mutation and selective pressure play an important role in shaping codon usage bias in P. umbellatus genes. Twenty-two optimal codons were identified as being biased toward codons ending with G or C using the high expression superior codon analysis method. This study will lay a foundation for future research on genetic engineering and molecular evolution in P. umbellatus.