A micro．method for the molecular weight determination of polyamides by the end-group titration has been studied． A sample of 10—20 mg was dissolved in 4 ml of neu-tral benzyl alcohol at 120—170°and then titrated under bubbling of nitrogen with 0.02 N methanol-water solution of potassium hydroxide and hydrochloric acid．by using the syringe-micrometer type ultramicro burettes which read to 3.10-4 ml．The indicators used were phenophthaleinthymol blue (6：1) for carboxyl-group and bromophenol blue for amino-group．The anhydrous neutral benzyl alcohol may be prepared by the adsorption chromatographic method with Al2O3-CaO-NaHCO3 as adsorbents．The oxidation of benzyl alcohol to acids may be avoided in the absence of oxygen and light．