This research was aimed at knowing the students’ ability and problems faced by the students in writing descriptive text about school environments. This research used descriptive method with 147 students at tenth grade of SMK Bakti Purwokerto in the academic years 2015/2016 as the populations. There were 51 students who were chosen as the sample. It was taken by random sampling. Written test was given to the samples in the form of creating descriptive paragraphabout school environments. The result of this research showed that there were 27 students who got average score in fair category and 24 students in good category. The students’ writing ability belonged to fair category with the mean score was 17. Meanwhile, the students’ writing was analyzed based on the aspects of writing, such as content, organization, vocabulary, grammar and mechanics. The problems faced by the students were in vocabulary and grammar. There were three kinds of problems in grammar. Those were; sentence pattern (44%), Tense (33%), and Subject-verb agreement (22%).