"Hsing" is Wade-Giles, the older, and some people feel: more poetic, spelling system for transliterating Chinese into English.

The Chinese themselves have been using Pinyin for some time now (ie -- schoolchildren in China use it as a stepping-stone to pictography). It's generally considered official, and more rigorous, to boot. The pinyin spelling of "hsing" would be "xing".

The biggest transliteration issue in this case is that Chinese has two sounds which are close to the English "sh" sound. In Pinyin, these are written using "sh" and "x". In other words, shing and xing (pinyin spellings) are different words with different sounds to the Chinese ear, but not necessarily different sounds to the English ear--they both sound like "sh". Same goes for "ch" and "q"--"qing" sounds like "ching" to English audiences.