Background and aims: Internet gaming disorder (IGD) was proposed in Diagnostic and Statistical Manual of Mental Disorders of American Psychiatric Association as an area warranting more research attention. High prevalence of excessive Internet game use and related addictions has been reported in China, especially among youth; however, there is a lack of psychometrically and theoretically sound instruments for assessing IGD in the Chinese language. Methods: This study aimed to examine the psychometric properties of a Chinese version of the Internet Gaming Disorder Test (IGD-20 Test) among Chinese middle school (n = 569; Mage = 13.34; 46.2% females) and university students (n = 523; Mage = 20.12; 48.4% females) samples in Beijing, China. All participants voluntarily completed an anonymous questionnaire. Results: Confirmatory factor analysis results showed that the Chinese version of the IGD-20 Test had five factors (i.e., salience-tolerance, mood modification, withdrawal, conflict, and relapse). Measurement invariance was confirmed across the two samples. The test score was positively associated with the modified Young's Internet Addiction Test for gaming addiction. Concurrent validation was further demonstrated by the IGD-20 Test's positive correlation with weekly gameplay and depression symptoms. The latent profile analysis showed four different gamer classes (i.e., regular gamers, low-risk engaged gamers, high-risk engaged gamers, and probable disordered gamers), with the estimated prevalence of 2.1% of the last group. Discussion and conclusion: The IGD-20 Test was applicable to Chinese youth and its Chinese version generally demonstrated good psychometric properties.