This legal study approaches the problems of legal entity’s participant’s civil liability under the legal entity’s obligation. In the first part of this work a historical evolution of a legal entity and its participant is being revealed, author introduces to the variety of the theoretical doctrines of a legal entity, a conception and main features of legal entity are presented. Hereafter, a conception of a juridical person’s participant is analyzed, also the peculiarities of the participant’s legal status is passed in review in light of the limited and unlimited liability. This study also presents general conditions upon which the liability of legal person’s participant may arose. Thereinafter the problematical aspects of the limited liability juridical person’s participant liability under the juridical persons’ obligation are being discussed, attention is paid to the advantages and drawbacks of the limited liability and also to the doctrine of piercing the corporate veil in Lithuanian and foreign jurisprudence and judiciary practice. This work also reveals the positive and negative features of unlimited liability in the context of social and economical life, brings up problems concerning unlimited liability legal entity’s participant liability under legal entity’s obligation in exaction, insolvency and liquidation procedures. Finally, conclusions and suggestions to the legislator and judicial bench are being brought up.