Magnetic manganese ferrite powder is synthesized via chemical co-precipitation and hydrothermal techniques are using chemical compound in metallic chlorides of manganese and iron. As a precipitant agent nemely sodium hydroxide (NAOH) are used. The performed calcinations temperature at 700°C for 6 hours. The investigation of the structural compound are prepared sample was identified through X-ray diffractometer (XRD) and scanning electron microscope (SEM) with Energy Dispersive X-ray (EDAX). The investigation of magnetic property of manganese ferrite nanoparticles reveals that the saturation magnetization is high, hysteresis in the region of measured field strength.