Magnetic properties of sintered Fe-79Ni-4Mo cores made of centrifugal atomized powders were investigated. $H_{c}$ and $mu_{a}$ of the cores sintered at $1350^{circ}C$ for 2 hours measured at 60 Hz at a magnetic field of 10 Oe showed the best properties. Particularly the properties of $H_{c}$ and $mu_{a}$ measured at low field (< 0.2 Oe) were found to increase with increasing the particle size of the core samples. It resulted from the domain wall motion depending on the grain size of sintered bodies. The best D, C magnetic properties of $H_{c}$ and $mu_{max}$ were 0.085 Oe and 40000, respectively. A, C properties of the same cores showed the $mu_{a}$ of 11000. The magnetic properties of sintered cores always exhibited an enhanced AC/DC performance by using the powders mixed with two different particle sizes. Those properties of cores are expected to apply for current transformer.