The indirect ELISA method with rabbit anti-SRSV superimmune serum on detecting small round structured virus(SRSV) in fecal specimen was established. The result was distinctly different in positive and negative controls, which demonstrated that the ELISA method established in this study was accurate and credible for detecting SRSV. Fecal specimens have been collected from 45 diarrhea patients in Beijing during the autumn and winter in 1998-1999. One specimen showed strong SRSV-positive result and two specimens showed weak SRSV-positive results. Furthermore, SRSV-like virion could be observed in the specimen with strong SRSV-positive result under electronic microscope with phosphate tungsten negative-stain and 60000-fold magnification. But no typical SRSV-like virion could be observed in specimens with weak SRSV-positive results. The rate for SRSV infection in diarrhea patients observed in this study was about 2.2%. The results implicated that SRSV infection was sporadic in Beijing during the autumn and winter seasons in 1998-1999.