Abstract: Statistical analysis on the density distribution of each layer was made based on the PSL(parallel strand lumber)pressed without glue. The result indicated that the density of each veneer strip after pressed met the normal distribution. The predicted value calculated by the model would be compared with statistical distribution range. When the pressure is lower than 5 MPa, the calculated value meets well with statistical distribution range. But when the pressure is 5 MPa, there is a great difference between them. And finally the density gradient model was confirmed. The result of face density scanning indicated that the density gradient model of PSL is accurate.