A highly fluorescent 2,2'-bianthryl derivative bearing urea groups (2) was prepared as an anion receptor. The UV-vis and fluorescence titrations of 2 in various organic solvents revealed that the association constants (K-11) were correlated with acceptor number and Swain acity of the solvents used, and tetrahydro-furan was found to strongly enhance the K-11 for Cl- and AcO- due to enthalpy driven complexation, in which naked eye detection of AcO- was achieved.