Three chondrites, Yamato-74160 (LL6), ALH-77260 (L3), and St. S¿verin (LL6) contain a considerable amount of the ordered FeNi, tetrataenite, in their metallic components. Natural remanent magnetization (NRM) of the three chondrites contains a highly stable component which can hardly be demagnetized by alternating magnetic fields up to 1800 Oe peak. The highly stable NRM component is identified to the NRM of the tetrataenite phase which has a large magnetic and optical anisotropy. By heating up to about 800 ¿C, however, the tetrataenite phase is broken down to the ordinary disordered taenite which has a much weaker magnetic coercivity.