Abstract: The liability insurance, in a broad sense, belongs to the property insurance. According to the “principle of indemnity”, in early times, the function of liability insurance is to fill up the insured’s actual monetary loss caused by assuring compensation liability; the insured only enjoys the “insurance payment claim”. However, the liability insurance now is the litigation insurance, and then it has functions of right protection, that is, the insurer needs to help the insured to exclude the “negative state” caused by the damage claims from the third party, and the unfavorable state is the loss of the insured. Meanwhile, the nature of the insured’s claim is the “legal protection claim”. The claim includes two parts one is the “exemption claim” helping the insured exempt from compensation liability and the other is the “defense claim” helping the third party claim for compensation. The theory of “legal protection claim” is the inevitable choice for the construction of the insured’s claim in liability insurance in the future.

Key words: liability insurance, insurance payment claim, exemption claim, legal protection claim             [