Imazethapyr, an herbicide belonging to the imidazoline family, is among the methods used to control Datura stramonium (D. stramonium), which has favorable chemical management of this herb. Six biotypes of Datura stramonium L. were gathered from the provinces of Alborz, Hamedan, Gilan, Kermanshah, Mashhad, and Qazvin in order to examine the effects of imazethapyr herbicide dosages on their physiological, morphological, and biochemical properties. The study was conducted between the years 2021 and 2022, in the research greenhouse of Dr. Shariati College in Tehran, in a RCBD manner with four replications and three levels of imazethapyr application, including no use as a control, reduced and usual doses of 0.5 and 1 liter per hectare were applied, respectively. The aforementioned treatments were administered once the seedlings had reached the stage of six to eight leaves. A sampling was performed a month after the treatments were applied. The findings of the second year confirmed the findings of the first year. According to the findings, the Alborz and Gilan genotypes had the highest relative water content reduction in leaves, and the Hamedan genotype had the most electrolyte leakage. Also, the genotypes from Hamadan and Gilan showed the greatest decrease in protein. The Gilan genotype was correlated with the greatest potassium and sodium increase. Based on the findings, it was determined that the genotypes of Mashhad and Hamedan were equivalent in terms of their responses to Imazethapyr since they had similar physiological and biochemical properties.