The utility model discloses a portable information channel tester, a serial communication port, include: casing, internal connection wire, information channel testing arrangement, insulating slider, metal probe, sliding guide, display device, information channel testing arrangement sets up the inside at the casing, display device with the information channel testing arrangement communication is connected and set up the front at the casing, lateral part at the casing is equipped with the groove, and the inslot is equipped with the sliding guide of two parallels, is equipped with insulating slider between the sliding guide, metal probe fixing is on insulating slider, and the metal probe can slide on sliding guide, adjusts suitable measuring distance, and metal probe one end runs through perpendicularly in insulating slider to be connected with information channel testing arrangement through the internal connection wire, then with gained information transfer to display device. The utility model has the advantages of being simple in structure and convenient in operation not only can easily manipulate alone, can improve the efficiency of work moreover, it is especially adapted in using widely.