Phototherapy is a therapy using radiation beam with high intensity. Its function is for the treatment or light therapy on infants jaundiced. However, the existing tools currently have the disadvantage that the absence of a temperature sensor which serves to monitor the temperature of the baby or the patient during the irradiation process takes place, then designed based phototherapy include temperature monitoring mocrocontroller ATMega 16 Phototherapy include temperature monitoring tool works automatically using ATMega microcontroller 16 and is controlled by a temperature sensor. Is the principle of power supply will provide voltage to each circuit block is a solid state relay, the minimum system and sensor circuit. During the irradiation process, the LM35 temperature sensor will monitor the baby's temperature. If in getting baby's temperature in a normal state, then the buzzer will sound Based on data retrieval has been tested timers 1 and 3 hours, testing the temperature of 35ºC, 36ºC and 37ºC on phototherapy in get some measurement results. It can be concluded that the smaller the value of the standard deviation, the more precise the data generated. And the smaller the value, the more accurate the measurement error is also data.