Abstract:Using the oligo nucleotides of both ends of barley (Hordeum vulgare L. ) calmodulin structural gene as primers, pea (Pisum sativurn L. ) calmodulin gene (CAM) was synthesized from RNA derived cDNA first strand through PCR before it was actually cloned and sequenced. Compared with CaMs of alfafa ( Medicago sativa L. ), rice ( Oryza sativa L. ), barley ( Hordeurn vulgate L. ), eel electroplax ( Electrophoridae ), Aspergillus nidulans and yeast ( Saccharomyces cerevisiae ), it has homology of 91.3% –60. 8%, while the change between C and T at corresponding position in pea CaM can often be observed. Analysis of the seven CaMs shows that some of them have one or two dominant nucleotide change pattern,their codon bias is also different.