Vessels bloodretrograde into theintravenous tube can cause some problems such as blood clotting, waste of time, interfere with the treatment process and the patient's anxiety. The aim of this study was the design of a device to warn the blood retrograde into the intravenoustube. Designed peripheral intravenous catheter, warns medical staff by alarming blood retrogrades into the intravenoustube. Changes in the blood concentration showed no significant effect on the sensitivity of the device. Certainly this practical angicatheter can be helpful in improvement of treatment process and also helps to patient's calm.