The commercial fibrin glue has been successfully employed in otologic surgery. It is biologically compatible adhesive with adequate tensile strength. But major problem of commercial fibrin glue is that the fibrinogen and factor XIII ard isolated from pooled human plasma, Therefore the risk of viral hepatitis and acquired immune deficiency syndrome can not be excluded, which is the potential hazard with any product derived from pooled blood sources. Autologous fibrin glue derived from ammonium sulfate precipitation would avoid this risk. In order to evaluate the purity and analyze the yield, we produced the autologous fibrin glue using ammonium sulfate precipitation and study of biochemical composition of this glue derived from 30 human doners was performed. The obtained results were as follows : 1) The mean fibrinogen of final product was 28ml/ml(range 13-57mg/ml). 2) The yield averaged 54.6%(range 22.3-74.4%). 3) The main protein in the final product was fibrinogen(mean 40.2%, range 22.1-59.5%). 4) Correlation coefficiency was 1.46 between plasma fibrinogen and glue fibrinogen. 5) Agarose gel electrophoresis demonstrated that predominant protein of final product was fibrinogen.