Objective To study a new method for extracting agarose. Methods In 1.5% agar solution, adding the cation resin exchanged by NH~+_ 4 to take off metal ions, then using the OH~ - basic resin to absorb agaropectin. Results and Conclusion The extracting rate was 57%, gel strength reached 560 g/ cm~ 2 , the agarose has good electricity function by measuring the gentian violet electrophoresis and the DNA gel electrophoresis, so it is suitable for bioche- mistry and molecular biology electrophoresis. It is a kind of simple and low cost method for extracting agarose which better than the EDTA- 2Na method and DEAE cellulose method.