Objective To establish a method to prepare anti-sodium estrone sulfate monoclonal antibody ( ESS-Mab) . Methods Balb/c mice were immunized by ESS. Immune methods were screened. The blood serum potencies were measured by indirect ELISA and the best consistence of antigen and the first antibody were confirmed with method of titration. Cell fusion was carried by using PEG method and McAb hybridoma was screened with the indirect ELISA. Results The best immunization method of mice was subcutaneously multi-point injection in mouse back with the dose of 200/100 μg ESS antigen five times. The fusion rate was 90. 2%. Hybridoma positive rate of ELISA screening was 4. 4%. Finally two cell lines 2C8 and 8A7 with good specificity and sensitivity were obtained. Conclusion The best immunization way is selected and indirect ELISA is set up effectively and reliably for screening and presenting ESS McAb. the hybridoma technique is able to prepare monoclonal antibody of anti-ESS successfully.