Here is studying the oxygen delignification of on industrial SNS hardwood pulp. This method allow the obtainment of normal delignified pulps with higher resistance characteristics thou those of the initial pulp. The speed and selectivity of the process, such as pulp's properties depend on temperature, time, alkali concentration and oxygen pressure. The best results are obtained on delignificatian at 150 C, 0,5-1 hours duration, and 10 g/L sodium carbonate concentration.