Which city are you asking about or are you asking about music stores and heavy metal in China in general? Presuming it's the latter, the answer is yes, there are music stores and concerts that play heavy metal in China. There are metal clubs in Beijing and Tianjin (13Club) and most live music venues across China put on metal shows from time to time. Guangzhou and Wuhan have quite a thriving metal scene.

If you are in Shanghai, there's Yuyintang http://yytlive.com/?lang=en which sometimes has rock shows, but mostly local artists. Occasionally they have some smaller acts from overseas such as punk bands from the US and Japan. Interesting place with cheap beer.

If you're in Shanghai looking for a real metal scene, there is actually a heavy metal bar called Inferno: http://www.cityweekend.com.cn/shanghai/listings/nightlife/bars/has/inferno/

Gotta love a bar in China that plays Pantera.