Abstarct: There is an international concern about the disposal or recycling of waste materials in the world, due to the increasing production of solid waste. One of the way to reuse solid waste is to use it in engineering and remediation of buildings or loose soil. The purpose of this study is to find a way to reuse a special type of plastic (bottles of buttermilk, soft drinks, mineral water, etc.) along with ash in geotechnical works to improve the soil. In this research, it Has been evaluated, the mechanical behavior of the sand of Anzali port, which has been reinforced and stabilized with different forms of plastic waste, fragments, strips and plastic sheets with different amounts, along with ash (Geopet)). California Bearing Ratio (CBR) tests have been performed on specimens with a relative density of 70% and also at optimum humidity. The results show that although polyethylene terephthalate (PET)fragment and strips have improved the mechanical behavior of sandy soils, the effect of Geopet reinforcement is more greater on improving soil mechanical behavior. The use of fly ash as a stabilizer in conjunction with Geopet has also had a significant effect on CBR values. Optimal use of these materials obtained in 7 days curing; Geopet with mesh dimensions of 1*1 in three laxyers with 15% ash content. Comparison between reinforced and unreinforced samples showed that in the optimal state, the CBR value improved by 174.9%.