Abstract: Green fluorescent protein (GFP) is a sort of protein produced by jellyfish (Aequorea victoria) and sea pansy (Renilla reniformis) which absorbs blue light and emits green fluorescence without exogenous substrates or co-factors, and the fluorescence can be easily detected with fluorescent microscope or fluorescence-activated cell sorter (FACS).Green fluorescent protein gene is an important new reporter gene that can express in living cells without other external substrate and no specific in species, tissues or cells at present.With features of sensitivity in detection, simplicity in manipulation, and reliability in result, GFP is an important reporter gene of practical. Being an effective selective marker, GFP has a great potential application in fields of cell, developmental and molecular biology.