This article aims to investigate the implementation of the Optimality Theory (OT) paradigm in the formation of Active Participle (AP) in quadrilateral verbs in the Arabic language. This approach involves morphological and contrastive linguistic analyses to understand the patterns of PA formation from quadrilateral verbs, with a focus on the hierarchy of criteria and candidate evaluation based on OT principles. The research methodology includes an in-depth study of various forms of PA produced by quadrilateral verbs, identifying rules and preferences that lead to changes in the word forms. The research findings indicate that OT provides profound insights into the complexity of the morphology of quadrilateral verbs, illustrating consistent patterns of change as well as variations depending on grammatical and semantic contexts. The implications of these research findings significantly contribute to the understanding of Arabic linguistic structure, morphological theory, and contrastive analysis methods. By paving the way for further research, this article suggests that paradigm serves as an effective conceptual framework to explain morphological phenomena in the Arabic language, enriching Arabic linguistic literature and supporting the development of advanced morphological analysis methods. This study opens avenues for deeper exploration of linguistic intricacies, fostering academic insights into the Arabic language's structural nuances.