High Pressure Heater is one of the heat exchanger type shell and tube in the plant consisting of a shell on the outside and a tube on the inside where the temperature of a fluid in the shell is different from the temperature inside the tube, resulting in heat transfer between fluid flows. The use of baffle inclination on the shell side serves to direct the fluid flow so that the flow occurs turbulence that can affect the temperature distribution on the shell side. This study aimed to determine the influence of baffle inclination angle on temperature distribution and fluid flow. The results showed that using variations in the angle of baffle inclination can increase the outlet temperature value and the higher temperature at a 20° variation in baffle inclination angle of 349.74 K, the pressure on the shell side decreases at each variation lowest value of 793.19 pa at 0° variation of baffle inclination and the velocity value produced is higher with the increasing angle of the baffle. Given the variation in baffle angle, the change in value in the high-pressure heater is caused by turbulence caused by baffle inclination on the shell side.