Gamers with Internet gaming disorder (IGD) dynamically regulate their psychophysiological responses during playing; however, analyzing instantaneous psychophysiological responses in these gamers has been limited by a lack of appropriate methods. We propose combining the Complementary Ensemble Empirical Mode Decomposition and Direct Quadrature methods to overcome this limitation. The related effect of abdominal breathing (AB) training (as a relaxing psychology method) on the distribution of instantaneous frequency (IF) was investigated by calculating median (IFmed), kurtosis (IFkurt) and skewness (IFskew), and 19 participants with high-risk IGD (HIGD) were found to have increased IFmed [massively multiplayer online role-playing game (MMORPG): 0.36 ± 0.08; first-person shooter game (FPSG): 0.34 ± 0.08] but decreased IFkurt (MMORPG: 5.98 ± 2.31; FPSG: 6.84 ± 4.61) and IFskew (MMORPG: 0.40 ± 0.69; FPSG: 0.64 ±1.04) during game-film stimuli compared with baseline and recovery states. After AB training, IFmed of these 19 participants (MMORPG: 0.24 ± 0.11; FPSG: 0.18 ± 0.06) decreased significantly. This study is firstly to observe the IF distribution of respiratory signal in gamers with HIGD; thus, this distribution may be used as a respiratory physiological marker of IGD risk.Clinical Relevance - This study analyzes the respiratory IF in gamers with Internet gaming disorder to investigate the maintenance of disorder behavior.