Abstract: In this study the coding sequence of the ICE1（GenBank Accession No. JX029153）in tea plant（Camellia sinensis）were analyzed with CodonW，CHIPS（Condon heterozygosity in a protein coding sequence）and CUSP（Create a codon usage table）programs，while compared with the genome of tea plant and ICE1 from 7 plant species. The results showed that ICE1 of tea plant was bias toward the synonymous codons with A and T. Compared with the codon usages of tea genome，the consequence indicated that only six kinds of amino acid codon bias was exactly the same. Further studies found that the ICE1 bases composition had greatly changed after monocotyledonous and dicotyledonous plants differentiating. The cluster tree based on the relative synonymous codon usage（RSCU）could not reveal the evolutional relations among the 8 plant species，whereas that based on the relative synonymous codon usage（RSCU）could reveal their evolutional relationship much better. There are 25 codons showing distinct usage differences between ICE1 of tea plant and genome of Escherichia coli，15 between ICE1 of tea plant and genome of yeast，10 between ICE1 of tea plant and genome of Arabidopsis thaliana. Therefore，the Arabidopsis thaliana expression system may be more suitable for the expression of ICE1 of tea plant.

Key words: tea plant, Camellia sinensis, ICE1, codon usage, codon usage bias, cluster analysis, cold resistance