There is provided a salt of 1-cyclopropyl-8-methyl-7-[5-methyl-6-(methylamino)-3-pyridinyl]-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid selected from the group consisting of citrate, hemi-fumarate, maleate, L-tartrate, mesylate, hydrochloride, potassium, and sodium salts.本發明提供1-環丙基-8-甲基-7-[5-甲基-6-(甲胺基)-3-吡啶基]-4-側氧基-1,4-二氫-3-喹啉羧酸鹽,其係選自由檸檬酸鹽、半反丁烯二酸鹽、順丁烯二酸鹽、L-酒石酸鹽、甲磺酸鹽、鹽酸鹽、鉀鹽及鈉鹽所組成之群組。