In this report a skin alkaline injury model was constructed using experimental rats and 2 N NaOH. We observed the effects of washing with a neutralizing agent on the subcutaneous tissue pH at 1, 10 and 30 min after injury and compared it with water-washing groups. In comparison with the water washing group, the peak pH values following the use of the neutralizing agent were significantly higher in the 1-min washing group, and significantly lower in the 10-min and 30-min washing groups. Changes in the pH values of the subcutaneous tissue after reaching a peak showed a similar course in the 1-min washing group, whereas in the 10 and 30 min washing groups there was a significantly different rate of decrease of pH. These results indicate that although treatment with a neutralizing agent directly after injury causes harmful effects due to the neutralizing reaction with a highly concentrated alkali. Subsequently with prolonged washing there is an effective reduction of the high pH.