The polycrystalline LiCo Fe PO was synthesized by solid-state reaction method. The crystal structure was determined to be orthorhombic with a space group of Pnma by x-ray diffractometer (XRD). The temperature dependence of the magnetization was investigated by superconducting quantum interference device (SQUID) magnetometer. Although LiCo Fe PO showed a typical anti-ferromagnetic behavior at temperatures below K, a rapid increase in magnetization was observed at temperatures below 9 K. The microscopic magnetic properties of LiCo Fe PO were characterized by Fe external field Mössbauer spectroscopy. At temperatures below 9 K, the magnetic hyperfine field showed a rapid increase, while the electric quadrupole splitting decreased rapidly. The and under external field of 4.8 T changed significantly compared to the value without external magnetic field. These are originated from orbital angular moment contribution by spin-orbit coupling at temperatures below 9 K, while orbital angular moment is quenched by the crystalline field due to distorted CoO (FeO ) asymmetric structure at temperatures above 9 K.