The present paper describes elementary analysis for biological materials by using a wave dispersive type X.M.A. (X-ray microanalyzer). The wave dispersive analysis has been considered to be unadequate for analyzing the elements of biological materials because analytical specimens generally lack any specialized elements incorporated in the materials, and also tend to be damaged and charged at higher accelerating voltage. To overcome these defficulties, the specimens were treated with a reagent which reacted with the materials to be analyzed and then coated with carbon by means of vacuum evaporation. Thus, berberine could be analyzed accurately with the wave dispersive X.M.A. after reacting with ammonium reineckate to give a berberine -Cr- complex, followed by coating with carbon. This method was further applied to determine berberine presented in Coptidis Rhizoma.