The comparison of strength property between kraft pulp ( KP ) and Alkaline Sulfite-Anthraquinone (AS-AQ) pulp for thicker cell wall fiber materials Larch and Quercus as examples was studied. The average coefficient of flexibility of Larch and Quercus are 0.6-0.7 and 0.45-0.50, respectively. The results showed that the strength property of thicker cell wall pulp is some what different from those reported earlier. The strengths of AS-AQ are all higher than those of KP for Larch and Quercus. For Larch, under same beating degree the breaking length of AS-AQ is 8-16% higher than that of KP, burst index 3-14% higher, folding endurance 30% higher,tear index slightly higher. For Quercus, the breaking length of AS-AQ is 5-10% higher then that of KP,burst index 10-15% higher, folding endurance 30-50% higher, tear index 5-15% higher. Under the same breaking length the tear index of AS-AQ pulp is significantly higher than that of KP for both Larch and Quercus.