A series of 9,10-bis(arylethynyl)anthracene derivatives (1−8) have been synthesized and their two-photon absorption (TPA) cross sections were measured by nanosecond fluorescence measurement and femtosecond Z-scan methods. The λmax values of these molecules are very similar and the values are near 800 nm. The /MW of the dipole increases with the conjugation length, whereas those for the quadrupoles decrease slightly with MW. Also, the /MW of the octupole is smaller than the dipole. In all cases, /MW of the quadrupoles are larger than the dipoles. Moreover, the results of the femtosecond Z-scan experiment indicate significant contribution by the excited-state absorption in . Noteworthy is the good agreement between the structure−TPA property relationships determined by both methods.