The invention provides a judging method and a judging device for an interference source in a
wireless local area network (WLAN). The method includes the following steps: forming a measuring report by each access point (AP) through scanning of an information channel, and structuring an information channel
quality assessment form according to the measuring report, wherein the information channel
quality assessment form is used for reflecting an interference condition caused by an environment factor to the AP; according to the information channel
quality assessment form, establishing an interference
condition assessment form, wherein the interference
condition assessment form is used for reflecting an interference condition caused by the AP to a neighbor AP; and according to the neighbor
condition assessment form, obtaining an interference source
list of the whole network. By the adoption of the method and the device, a source causing interference to a
system is found, so that a basis and an operation object are provided for a follow-up anti-interference operation, and therefore interference process to the network is finer and more precise, and the anti-interference operation which is repeated, invalid, and conflicting is avoided. The method and the device can be applied to an existing 802.11 a / b / g / n and later evolution versions, so that the whole network interference process in the method of planning as a whole can be achieved.