Abstract: In order to explore the preference and influencing factors of codon usage in the chloroplast genome of plants in the genus Roscoea, this study collected chloroplast genomes of 3 species of Roscoea, and calculated codon composition parameters using Codon W and CUSP software. Based on this data, ENC-plot, RP2-plot, neutral plot and additional analyses were conducted. The results showed that the codon usage patterns in the chloroplast genomes of 3 species of plants in Roscoea were mostly the same, with a preference ending in A/U. The ENC values of protein coding genes in all 3 species of plants were greater than 35. This indicates that the codon preference in the Roscoea is weak. The results of neutral plot, ENC-Plot and PR2-Plot analysis all show that natural selection is the main factor affecting the codon preference of Roscoea. The optimal codons for Roscoea tibetica, Roscoea humeana, Roscoea alpina were screened out at 9, 11 and 12, with a total of 6 codons, namely CUU, UCA, ACA, GCA, UAA and AGA, indicating that the codon usage pattern of the chloroplast genome in Roscoea is predominantly affected by the combination of mutation pressure and positive selection.