The low voltage system is directly associated with the consumer and proper earthing is vital for the equipment as well as personal safety. But so far， little attention has been given to standards concerning low voltage system earthing in China， resulting in lots of defects in part of the standards. It is for this reason that the authors have explored extensive domestic and international standards and have some of them compared. For the inconsistency existing between these standards， an analysis is made and conclusions are drawn. By referring to the IEC standards， the deficiency of the domestic standards are pointed out， including improper terminology， additional earthing and earthing sharing. Scenarios for additional earthing and earthing sharing are generalized and revision suggestions are offered.