Abstract:A model system for gene electro-transfer into protoplasts of Chinese cabbage and cucumber was established by using calcein, FITC-IgG or ethidium bromide-plasmid DNA as fluorescent markers. Changes of permeability of protoplasts and it‘s kenetics during electroporation were investigated. The transfer efficiency (T) and survival rate (S) of protoplasts were found to be dependent on electric parameters (field strength, pulse number and pulse duration). The highest TS Value (T×S) was obtained at 4×2.8ms× 400V/cm for Chinese cabbage protoplasts and 4× 2.8ms × 300V/cm or 1 ×280ms× 1000V/cm for cucumber protoplasts. The CAT gene was expressed in protoplasts of cucumber after introduction of pUC12-CAT plasmld by electroporation. Heat shock pretreatment (45℃, 10min) increased gene-transfer efficiency.