Fashion designers are presented with a range of different principles for pattern cutting, and interest in this area has grown rapidly over the past few years, due to both the publication of a number of works dealing with the subject in different ways, and the fact that a growing number of designers emphasize experimental pattern cutting in their practices. Although a range of principles and concepts for pattern cutting are presented from different perspectives, the main body of these systems, traditional as well as contemporary, is predominantly based on a quantified approximation of the body. As a consequence, the connection between existing theories for pattern construction and the dynamic expression and biomechanical function of the body are problematic. While designing and making patterns for women's garments it is important to know the principles of dart manipulation.Dart Manipulation aims to develop bodices with different dart placement through dart manipulation and test fit the same. In terms of clothing, modular is a dressing system that contains several detachable small components. Each component can be adjusted independently and separately without affecting other components. This system can maximize the possibility of each garment by rearranging or transforming components into different combinations. The research aims to that, modular design concept and the dart manipulation technique work well together. Modular design concept and the dart manipulation technique provide us with fashion designs characterized by unique style lines. Modular design concept meets the user's needs. Access the best techniques that can be applied for designing women's clothes. According to the evaluation of designs, the best designs that took the highest scores were designs no. (1, 5 and 7), according to that, the style lines used in these designs are unique. Using striped fabric emphasized these lines. Dart manipulation technique and modular design can work well together in fashion designs. Snaps are an appropriate fastener tool to remove and/or add modular pieces to the designs and help consumer to change the final appearance of garments which meets his needs. The slash and spread technique and panels based modular system are suitable for achieving the research objectives. Dart manipulation technique and modular design added aesthetic values to the designs. The designs (4, 6) had the lowest scores.