In developing personal and professional growth, English Language Teaching students are imposed to develop writing skills as the act to reflect on their teaching experiences more effectively. This reflective process becomes actionable in their reflective writing based on experiences with self-regulated learning (SRL). With the growth of technologies in recent years, in performing self-regulated learning is often facilitated by a variety of tools and technologies, which one of the prominent examples is Artificial Intelligence (AI) Chatbots. This study intends to find out the effectiveness of utilizing AI Chatbot (ChatGPT) as an instrument to support self-regulated learning in improving the reflective writing skills of 40 students in the eighth-semester of English Education department at UIN Walisongo Semarang in 2024/2025 academic year. The study used explanatory sequential mixed method with quantitative and qualitative approaches. The instruments of research used are tests and interviews. The collected data are statistically analyzed using the SPSS software to determine the independent sample test (hypothesis test), which resulting in a Sig. (2-tailed) value of 0.000 (< 0.05), indicating that H0 is rejected, and Ha is accepted. Furthermore, the interviews results indicated that most students reveal an optimistic attitude against demonstrating self-regulated learning utilizing the AI Chatbot. It can be drawn to conclusion that the utilization of AI Chatbot efficaciously improves reflective writing proficiency of the students in the eighth-semester of English Education department at UIN Walisongo Semarang.