The article explores the influence of the mother tongue (Vietnamese) on practicing to develop first-year students’ English writing skills at Thu Dau Mot University. Analytical data was collected from 100 first-year students majoring in English Language at the Faculty of Foreign Languages - Thu Dau Mot University. Research results show that students are still greatly influenced by Vietnamese (first language) in the process of practicing English writing skills. Among the students surveyed, up to 58.4% said they were still influenced by the way of thinking in Vietnamese, and then switched to English to follow the writing style of Vietnamese. … The remaining % said they had practiced writing in English through many writing activities at English centers and had practiced writing through thinking in English. The rest of the article proposes some solutions to help students overcome the above barriers to develop effective writing skills.