^{The data of the article "Development and Validation of Artificial Intelligence assisted Self-regulated Second Language Learning Scale：An Empirical Study of Chinese Secondary EFL Learners"}

Self-regulated learning is an important ability for English as a foreign language (EFL) learner. With advances in artificial intelligence (AI) technologies, AI-powered learning environments offer new opportunities for learners’ self-regulated second language (L2) learning. However, evidence for the systematic and valid instruments to measure self-regulated L2 learning strategies of secondary school EFL students in an AI-powered learning context is far from robust. This study aimed to develop a reliable and valid scale to clarify the constructure of AI in self-regulated L2 learning and examine the status quo of self-regulated L2 learning strategies employed by secondary school EFL learners in an AI-powered learning context. Based on relevant literature, the AI-assisted self-regulated L2 learning (AI-SRLL) scale comprised cognitive, metacognitive, behavioral, and motivational regulation aspects. Drawing on the response from 2480 Chinese secondary EFL students, the validated AI-SRLL had 27 items for junior version and 21 items for senior version, addressing six dimensions: plan making, environment structuring, help seeking, task strategies, effort regulation and self-evaluation. Results demonstrated the AI-SRLL has good measurement validity and reliability with strong invariance across junior and senior high school students. The overall use of AI-SRLL strategies and the associations between the strategy use and their individual factors also be discussed. Our results draw attention to the pedagogical orientation for teachers of English as a foreign/second language in helping and motivating students become adaptive learners with self-regulative process in an AI-powered learning environment.