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Recently many endohedral metallofullerenes such as M@C 74 , M@C 80 , and M@C 82 (M: metal atom) have been successfully isolated by the high performance liquid chromatography (HPLC) technique. 1-5 Some M@C 60 were prepared in primary soots by an arc-heating or a laser-vaporization method, 6-9 but the isolation of M@C 60 has not yet been achieved because of the difficulties in extraction; only the extraction of Ca@C 60 with pyridine has been reported so far. 10,11 Recently we found that aniline is a suitable extraction solvent for Ca@C 60 and Sr@C 60 . 12 For the isolation of M@C 60 by an HPLC technique it is important to find a suitable extraction solvent for M@C 60 . In the present study, we report the successful extraction of Y@C 60 , Ba@C 60 , La@C 60 , Ce@C 60 , Pr@C 60 , Nd@C 60 , and Gd@C 60 with aniline under an air atmosphere.The soots containing M@C 60 (M: Y, Ba, La, Ce, Pr, Nd and Gd) were prepared by the arc-heating of the M x O y /graphite (M x O y : x ) 2 and y ) 3 except for BaO, CeO 2 , and Pr 6 O 11 ) rods (Toyo Tanso; M concentration: 0.8 mol % except for Ba (0.3 mol %)) at 25 V and 80 A under 100 T of He atmosphere. We then tried 48 solvents 13 to extract Ca@C 60 , but had success only with aniline and pyridine. Therefore the extraction of M@C 60 was tried with aniline (Wako Pure Chemicals: GR) as well as three representative solvents of benzene, toluene