The background music has been proved to be an indispensable part in every successful video game. At the same time, all the video game designers and players hope video games could be as immersive as possible. Present research aimed to make an investigation about the role of video games background music in the influence of players' subjective immersion. Eighty participants were employed according to their game experience to join the experiment. All of them were assigned in pairs to finish a same video game synchronously with local area network. One was with earphone while the other not. After 20 minutes' gameplay, they needed to complete three missions (questionnaire, task after game and time distortion) with the purpose of detecting their immersion during video game. The results showed that the participants with background music got significant higher scores from questionnaire, performed worse in after-game task and expressed more serious time distortion than those participants without hearing background music. But these changes just happened to low gamers in the questionnaire and time distortion. Besides, correlations were made to find that only the questionnaire scores and time distortion were significantly related. These results of present research showed that background music did increase participants' immersion. But this improvement was likely just happened in low gamers.