This A person can interact with communication; communication can be established well if there is a two-way interaction or someone has the ability not only in expressive language but also in expressive language. Autistic children have limitations which are shown by the inability to express themselves effectively, so the child feels pressured to be able to express. Limitations of language skills can also cause emotions for children with autism because autistic children cannot express their wishes through communication messages. This study aims to improve the expressive language skills of autistic children in Banjarmasin SDLB YPLB through the use of the PECS (Picture Exchange Communication System) method. The method used in this study is a quasi-experimental design with a time series design (O1 O2 O3 O4 X O5 O6 O7 O8). Subjects in this study were autistic students of grade IV SDLB YPLB in Banjarmasin. Data collection techniques use tests and documentation. Data collection instruments use verbal instructions and documentation tools. Data analysis techniques in this study used descriptive statistical data analysis. From the results of the expressive language ability of students at pre-test results obtained O1 = 27.5 O2 = 32.5 O3 = 32.5 and O4 = 35. After being given treatment using the PECS method to improve the ability of expressive language can be seen from the activities of students during the learning process using the PECS method looks very enthusiastic and active. While the expressive language ability of students increased during the posttest with the results of O5 = 82.5 O6 = 87.5 O7 = 95 and O8 = 100. The ability of students to be seen from students can answer questions starting from exchanging objects that have been provided, mentioning, showing, up to composing several pictures to form collapsed sentences. Thus it can be concluded that the use of PECS media can improve the expressive language ability of grade 4 autistic children in Banjarmasin SDLB YPLB. Keywords—PECS method; expressive language; children with autism