The critical micelle concentration (CMC), micelle ionization degree (alpha), Krafft point (KP), and chemical stability in water of sodium and calcium salts of the title surfactants, CmH2m+1NHCO(CH2)(n)OSO3Me, abbreviated as m-n-Me (Me = Na, 0.5Ca), have been investigated as a function of the numbers in and n of the hydrocarbon chain length and the spacer methylene chain length, respectively. For the m-n-Na series, the CMC was reduced with increasing both the spacer methylene chain length in = 1, 3, 5) and the hydrocarbon chain length (m = 12, 14, 16). The value of the ratio of reduction in log CMC for m to n was found to be just 4:1, suggesting that the spacer methylene chain is less hydrophobic than in the alkyl chain. Inclusion of an amide linkage near the headgroup in alkyl sulfates leads to a significant increase in the micelle ionization degree and to an increase in Krafft temperature. Furthermore, we found a striking and interesting exception in the Krafft temperature for the sodium and calcium salt pair of m-l-Me homologues. The KP of the 12-1-0.5Ca surfactant was found to be below 0 degrees C and was lower than that of the corresponding sodium salt (25.6 degrees C). This phenomenon is believed to be the first observation that the KP of the divalent salt is lower than that of the monovalent salt having the same surface active ion.