The present invention provides a method for protecting a real estate tenant, which includes : a right information acquisition/storage step in which a web server acquires right information on registration certificate for a lease real estate of a tenant who subscribed as a member and stores the information to database; a market price information acquisition/storage step in which the web server acquires market price which can be applied to the lease real estate from a market price information server and storing the market price to the database; a sell price ratio information acquisition/storage step in which the web server acquires a sell price ratio which can be applied to the lease real estate from an auction information server and stores the sell price ratio to the database; an estimated auctioning cost calculation/storage step in which the web server calculates an estimated auctioning cost which is to be consumed for auctioning of the lease real estate and stores the estimated auctioning costs to the database; and an estimated return deposit calculation/notification step in which the web server calculates an estimated return deposit which the tenant can receive using the right information, market price, sell price ratio, estimated auctioning costs and deposit paid by the tenant and notifies the estimated return deposit to the tenant.(110) Web server(AA) Tenant(BB) Web server access and member subscription(S110a) Acquiring right information for a lease real estate from a registration certificate server(S110b) Storing the right information(S120a) Acquiring a market price which can be applied to the lease real estate from a market price information server(S120b) Storing the market price(S130a) Acquiring a sell price ratio which can be applied to the lease real estate from an auction information server(S130b) Storing the sell price ratio(S140a) Calculating predicted auctioning costs for the lease real estate(S140b) Storing the predicted auctioning costs(S150a) Acquiring a balance of loan of the tenant for the least real estate from a loan information server(S150b) Storing the balance of loan(S160a) Calculating predicted return deposit and appropriate deposit increase for the lease real estate(S160b) Storing the predicted return deposit and appropriate increase in deposit(S160c) Receiving the predicted return deposit and appropriate increase in depositCOPYRIGHT KIPO 2014