The indoor distribution system for mobile communication is used to improve the performance of mobile communication signal coverage in large-scale physical buildings. The installation requirement of earthing and bonding for this system is still lack of clear guidance in the existing Recommendations, i.e. ITU-T K.56, K.97, K.112, K.120. The purpose of this Recommendation is to give a practical guidance on the earthing and bonding for the main configuration type of indoor distribution system in large-scale physical buildings to minimize the risk of damage to equipment and possible injury considering of lightning protection and safety.