A blood testing meter with a fool-proofing function has a measuring display unit, a connector and a blocking structure. The connector is mounted in the measuring display unit and has at least one guiding groove, and the at least one guiding groove is formed through an outer side of the measuring display unit. The blocking structure is mounted on the outer side of the measuring display unit and is adjacent to an opening of the connecting groove. When the blood test strip is inserted from a wrong direction into the connector, the slot would be engaged with the blocking structure to prevent the blood test strip from being inserted into the connector.
