This paper presents an experimental work of using crushed glass mixed with the poorly graded sandy soil to investigate the possibility of shear strength parameters improvement using the direct shear test. The crushed glass is sieved and prepared for seven sets of percentages, the collected percentages of crushed glass represented a mix of glass retained on sieves No. 4, No. 8, No. 30, No. 100, and No. 200 and were added as a weight ratio of the sample for many cases. The main results of this work show that the mixing 10% of crushed glass for sieves No. 8, No. 200, and No. 50 increase the angle of internal friction of poorly graded sand (Ø˚) about 15%, 3%, and 29% respectively, and mixing 10% of crushed glass retained on sieve No. 4 decrease Ø˚ about 40%.