The coding sequence of green f luorescent protein gene was cloned under the control of carp ..-actin gene promoter. A fish expression of green fluorescent protein gene recombinant was constructed. The recombinant gene was transferred into fertilized zygotes of goldfish ( Carassius auratus) via micro injection after Pvu .. linearing . The green f luorescence was visualized within 48 h following transformation. The transformation and expression of green fluorescent protein was demonstrated by PCR and Southern blotting. In Southern hybridization analysis, transformations got positive signals. The results indicated that the green fluorescent protein gene had integrated into goldfish genome.