During the process of cultivation of salt-tolerant nitrifying bacteria, the increase in NaCl concentrations was carried out in two different manners. The NaCl concentration in reactor A was increased by increment of 5 g/L, while the NaCl concentration in reactor B was increased by increment of 2.5 g/L. The impacts of NaCl content on the fresh culture and two acclimated cultures were investigated, which focused upon the changes of the specific ammonium oxidation rate (SAOR) and specific nitrite oxidation rate (SNOR). The results indicated that fresh nitrifiers were severely inhibited by high salinity. At NaCl concentration of 25 g/L, ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) completely lost the nitrification capability. After 46 days of acclimation, the nitrifying bacteria could be adapted to the saline wastewater. The average SAOR and SNOR in reactor B were slightly higher than those in reactor A, which meant that low increment in salt concentration may be in favor of the development of salt-tolerant nitrifiers. But the two NaCl increasing approaches did not affect the SAOR and SNOR too much. Salt-tolerant nitrifiers could be well developed with the two acclimation manners.