Abstract: A water level and temperature detector alarm device and more particularly to an alarm device which includes a buoy type detector to alternately detect water level or water temperature so as to provide an audio alarm signal through a buzzer when water level or water temperature reaches the predetermined range. The detector is connected to the expansible end of a conduit and includes a sleeve having set therein two reed switches and a thermswitch and having mounted thereon a body which includes therein a circular magnet. An alarm device is connected to the other end of the conduit which is having a movable positioning rack mounted thereon for positioning of the whole assembly. Following the rising of water level, the magnet of the buoy alternatively drives the reed switched to turn on the alarm device to buzz or, when water temperature reaches the predetermined range, the thermoswitch will be turned on to drive the alarm device to buzz.