Abstract: We used CHIPS, CUSP and Codon W online programs to confirm the codon bias of the complete coding sequence of PPDK in the grain Amaranthus hypochondriacus, then compared the codon bias with PPDK genes from different plant species. We constructed a phylogenetic tree based on codon bias to provide a basis for selecting appropriate PPDK receptors for A. hypochondriacus by high-photosynthesis gene engineering. PPDK in A. hypochondriacus and several other dicotyledonous crops was biased toward synonymous codons with A and T at the third codon position, but Zea mays, Oryza sativa and other monocotyledons use the end of the G or C codon. Phylogenetic analysis suggested that PPDK of A. hypochondriacus was evolutionarily closer to dicotyledons such as Solanum tuberosum and Medicago truncatula than the monocotyledons Z. mays, Sorghum bicolor and Echinochloa crusgalli. However, O. sativa is an exception in that the codon bias of PPDK is closer to that of dicotyledons A. hypochondriacus than the monocotyledons Z. mays or S. bicolor. To select the appropriate protein expression system, we compared the PPDK codon bias expression in A. hypochondriacus and Escherichia coli or yeast. Differences between A. hypochondriacus and yeast expression were less than between A. hypochondriacus and E. coli. The yeast system may be more suitable for expressing PPDK of A. hypochondriacus.