An alert device for use with an intravenous drip, comprises two induction ends and a control unit. The control unit comprises a circuit module, an alarm module and a power module. The two induction ends are located on a pipe of the intravenous drip and are contacting with an injection solution inside the pipe. The two induction ends are electrically connected to the control unit by wires. The circuit module detects the induction ends to determine whether the induction ends are in an open-loop status or not. The circuit module connects to the alarm module. The power module supplies power for the control unit. The induction ends uses the injection solution as a conducting means to form an electrically closed loop when the induction ends do not contact with the injection solution, the induction ends become an open-loop, and thus the alarm module generates alarm signals.
