The present invention relates to a P2P loan service system and method of an online personal bank providing a crowd funding function of investors who are provided with capital guarantee insurance services. When a P2P loan of an online personal bank is serviced on a fintech market by using an application of a PC, a smart phone, or a tablet PC, a capital guarantee insurance is provided to safely guarantee the principals of multiple investors having deposits/installment savings, stocks, real estates, and bonds. After making an investment contract through crowd funding, investment is attracted. After an online personal bank evaluates the credit and loan of a loan applicant on the basis of investment accumulated from investors, the online personal bank or the investors perform contract agreements and loan contracts directly with the loan applicant. Then, the online personal bank or the investors directly provide a P2P loan service to the loan applicant. A capital guarantee insurance service for guaranteeing the principals of investors during crowd funding of the investors is provided to the online personal bank. A P2P loan service can be provided from a personal to an enterprise, from an enterprise to a personal, or from a personal to another personal, and thus incomes of an online personal bank can be created.(AA) Loan applicant(BB) Registration(CC) Loan(DD) neobank financialrelay platform(EE) PR(FF) Interest paid(GG) Investor(HH) Service of loan from a personal to a personal, from an enterprise to a person, and from a person to an enterpriseCOPYRIGHT KIPO 2017