Abstract: Selectable marker genes were widely used in the transgenic plants. However， these genes based on the resistance to antibiotic and herbicides are redundant since transgenic plants have been selected and identified. Due to the presence of selectable marker gene and its products， the environment pollution and food safety of transgenic plants are strongly concerned by consumers. With the development of transgenic technology， it is very important to eliminate the selectable marker gene in transgenic plants. In this review， utilization of selectable marker gene， methods of marker gene excision consisted of co\|transformation， site\|specific recombination， intrachromosomal recombination， recombination by transposon， removal of chloroplast marker gene， regeneration of direct marker\|free plants， as well as the developmental directions of this technology were discussed.

Key words: selectable marker gene, co\, transformation, site\, specific recombination, transposon, chloroplast transformation