A diagnosis apparatus and a method for a failure node and a portable terminal. In an implementation, the diagnosis method includes: transceiving packets of a suspected failure node and its neighboring nodes within a period of time are monitored; the monitored packets are parsed, to obtain types, sources and signal strengths of the packets; a status of the suspected failure node is determined according to the obtained types, sources and signal strengths of the packets; and the determined status of the suspected failure node is displayed. Hence, a cause for a node failure is diagnosed without changing an original network and without limiting on hardware and software of a node within the network.
