To further study the properties of P53 suppressor gene, the 3-base periodicity of P53 coding sequence (CDS) and the corresponding mRNA are analyzed. And the codon biases of P53 CDS and mRNA are discussed through analyzing their relative synonymous codon usage and quasi relative synonymous codon usage values. The results show that the CDS of P53 exhibits 3-base periodicity, whereas the corresponding mRNA of P53 does not, and that the P53 CDS has a stronger bias towards C and G ending codons than the mRNA. This suggests that the 3-base periodicity is closely related to the codon usage bias of P53 gene, and the degree of codon bias has an effect on the 3-base periodicity, which further explains the difference in 3-base periodicity between P53 CDS and mRNA from the point of view of biology. This characteristic of P53 gene may be useful in increasing the correct rate of gene recognition and the extensive investigation of P53 gene.