Abstract: Gus genes controlled by several kinds of regulator sequences were introduced into citrus protoplasts respectively by PEG and lipofectin mediated transformation.The transient expression of gus gene in citrus protoplasts had been investigated.The expression level of the citrus protoplasts transformated with plasimid pBI121 and p35SGSINT (both gus genes were controlled by CaMV35S promoter) was higher than that transformated with plasmid pAT13 (gus gene controlled by Adhl promoter) and pRGN73 (gus gene under control of rice rbcs promoter).It was found that intron increase the expression level in citrus protoplasts.