The apparent acid dissociation constants of N-cyclohexylglycine and N-β-naphthyl-glycine have been determined to be PK_COOH=2.70, PK_R3NH3⁺=9.83 for the former and PK_COOH=2.26, PK_{R3NH3⁺=4.46 for the later by pH method at 25° in 30% ethanol solution in the presence of 0.10M sodium perchlorate.It was found that N-cyclohexyl-glycine as a base is comparable to that of glycine and N-alkylglycines, as expected, while the basicity of N-β-naphthylglycine is quite different from that of its isomer, N-α-naphthylglycine.These results evidently support our previous interpretation on the abnormally high basicity of N-α-naphthylglycine that steric effect due to the 8-hydrogen on the naphthalene ring upon the proton on the amino group was responsible for such an anomaly.}