Today, implementation of projects is necessary for organizations' mobility, dynamism and development as well as guaranteeing their survival. Since environment is constantly changing, the growth of quality concepts has also been taken into consideration due to the demands of customers and increasing complexity of industrial projects at the same time. This paper focuses on analyzing the key attributes of quality in gas transmission pipeline projects using gas structural equation modeling enabling a method to improve construction quality of this type of projects. In this regard, attributes (constructs) of quality extracted from research were classified into 6 elements of the highest quality project, least quality project, high quality project, low quality project, medium quality project, ideal quality project using LISREL statistical analysis tool and then the adaptability of the whole conceptual model was fitted. According to the interpretation of the results from structural equation modeling and factor loading, the representatives of the 6 classes including attributes of requirement consideration, integration, flexibility, specialism, continuity, normally(consumption energy), foresight, good documentation, technology oriented, conformance to standards, effective supervision and nice were selected. It is clear that considering these attributes is essential to achieve the desired quality in project implementation. Although, regarding all constructs can lead to success of the project.