PURPOSE: To obtain a stabilized isocyanate composition by simultaneously suppressing yellowing property and white turbidity over a long period to stabilize an isocyanate compound.
CONSTITUTION: Phenol of 10-5000ppm, especially 100-200ppm is added to an isocyanate compound (especially aliphatic polyisocyanate, preferably xylylene diisocyanate) to stabilize the isocyanate compound. By this method, the occurrence of white turbidity by self polymerization and coloring with the passage of time are suppressed, and the isocyanate compound exhibits excellent storage stability. Phenol especially exhibits an outstanding stabilizing action on unstable xylylene diisocyanates. The lowering in purity of the isocyanate compound is also suppressed by addition of the phenol and the effect is remarkably exhibited in the case of the aliphatic polyisocyanates.