Chassis frame of a vehicle

A chassis frame of a vehicle comprising:

• frame side members respectively disposed at opposite lateral sides of the vehicle while extending lengthily in a forward or rearward direction of the vehicle;
• at least one battery cross member installed at an upper side of the frame side members to extend lengthily in a lateral direction of the vehicle while being spaced apart from the frame side members, the at least one battery cross member being configured to mount a battery at a lower side thereof;
• and
• side protectors installed at opposite ends of the at least one battery cross member in a state of being spaced apart from the frame side members toward the lateral sides of the vehicle, respectively, to withstand lateral impact force from the vehicle.