In order to satisfy ~(14)C measurement with the new developed 200 kV single stage electrostatic accelerator mass spectrometer,the sample preparation processes for ~(14)C were investigated.The graphitization experimental conditions for H_2-Fe,Zn-Fe and Zn-H-Fe methods were optimized on self-designed ~(14)C sample preparation system.The beam current of ~(12)C-for all prepared samples can reach 15-40μA and its stability is better than 0.2%.The ~(14)C measurement shows that the lower particle number ratio of ~(...