The advancement of information technologies has led to increased attention to AI chatbots as valuable tools for computer-assisted language learning (CALL), drawing the attention of both academic scholars and industry practitioners. However, there remains limited understanding regarding the adoption of AI chatbots, specifically within the context of the English language. To address this existing research gap and examine the perception and motivation of usage of ChatGPT, this research employed the hedonic motivation system adoption model (HMSAM) to examine the adoption of ChatGPT. Employing structural equation modelling (SEM), a comprehensive investigation was conducted using data sourced from 189 valid responses obtained through an online survey administered to Chinese international students who are currently enrolled in British universities. The findings reveal that the research model effectively elucidates the elements influencing the adoption of ChatGPT in English learning. Notably, boredom, joy, focused immersion, and control emerged as significant mediating factors pertaining to the link between perceived ease of use and behavioural intention. These findings offer meaningful perspectives for upcoming researchers and practitioners in English language teaching and learning, contributing to promoting innovation in this domain.