A method and system is provided for safe online commercial transaction. When a safe transaction service provider receives a request from a first party for obtaining a transaction performance guaranty service, the safe transaction service provider processes the request by underwriting the first party. If the underwriting is successful, the transaction performance guaranty service is provided to the first party which binds a transaction performance guaranty to an online commercial transaction involving the first party and guarantees the first party's performance when the first party and a second party enter the online transaction.