This research is “The development of A Prototype of Phototherapy with Light Blanket for Neonatal Jaundice” has purpose for Prototype of Phototherapy with Light Blanket for Neonatal Jaundice. Neonatal Jaundice a common problem in the newborns the case is high level of bilirubin need to be treated quickly to prevent disability from bilirubin into the brain. Phototherapy treatment is the most popular this research is the application of microcontroller PIC 16F877 a main control device use a tube LED Super bright as the light source and use optical fiber distribution of light blanket for treatment with micro controller process commands and an adjustable light intensity and set the time off and command through the circuit by LED. Light source light to work through the fiber optic to the end of the line spread a light blanket the measured light intensity by using light intensity meter measure to LUX from with Light Blanket of all 6 times spaced apart 1 cm. The first phase to measure the light intensity adjacent to the blanket light 5 cm by measuring about 30 times the measurement results found at first stage the light intensity 47lux the second stage is 1 cm light intensity 35.56lux the third stage is 2 cm light intensity 28.06lux the fourth stage 3 cm light intensity 19.60lux the fifth stage is 4 cm light intensity 14.16lux and the sixth stage 5 cm light intensity 11lux.