This study aimed to evaluate the effectiveness of using the project entrance to develop the knowledge and environmental skills of the students of the vocational preparatory stage through the agricultural field course. An environmental project was developed from some of the courses of agricultural field in the second grade vocational preparatory curriculum. The sample size in this study was 60 students in the second-grade vocational preparatory school, divided into 30 students to represent the control group and 30 students to represent the experimental group. The results of the study showed that there was a statistically significant difference between the mean of the experimental group and the control group in the post-application in favor of the experimental group. The environmental project has been implemented, which confirms the effectiveness of using the project entrance in the development of knowledge and environmental skills. Keywords: project learning, environmental knowledge, environmental skills, agricultural field, vocational preparatory curiculum.