Disclosed is a pyridine substituted 2-aminopyridine protein kinase inhibitor crystal, in particular relating to 5-((R)-1-(2,6-dichloro -3-fluorophenyl)ethoxyl)-4'-methoxyl-6'-((S)-2-methylpiperazin-1-yl)-3,3'-bipyridyl-6-amine citrate crystal, a preparation method thereof, a crystal composition and a pharmaceutical composition. Also disclosed is a use of a citrate crystal of a compound of formula I in diseases associated with protein kinases. The citrate crystal of the present invention is superior to 5-((R)-1-(2,6-dichloro -3-fluorophenyl)ethoxyl)-4'-methoxyl-6'-((S)-2-methylpiperazin-1-yl)-3,3'-bipyridyl-6-amine or other salts of 5-((R)-1-(2,6-dichloro -3-fluorophenyl)ethoxyl)-4'-methoxyl-6'-((S)-2-methylpiperazin-1-yl)-3,3'-bipyridyl-6-amine in at least one of bioavailability, hygroscopicity, stability, solubility, purity, ease of preparation and the like.本申請案揭露了一種吡啶取代的2-氨基吡啶類蛋白激酶抑制劑的結晶，具體涉及5-((R)-1-(2,6-二氯-3-氟苯基)乙氧基)-4'-甲氧基-6'-((S)-2-甲基哌【口井】-1-基)-3,3'-聯吡啶-6-胺的檸檬酸鹽結晶、其製備方法、結晶組合物和藥物組合物，還公開了式I化合物檸檬酸鹽結晶與蛋白激酶有關疾病的用途，本發明的檸檬酸鹽結晶在生物利用度、吸濕性、穩定性、溶解性、純度、易製備等至少一方面優於5-((R)-1-(2,6-二氯-3-氟苯基)乙氧基)-4'-甲氧基-6'-((S)-2-甲基哌【口井】-1-基)-3,3'-聯吡啶-6-胺或5-((R)-1-(2,6-二氯-3-氟苯基)乙氧基)-4'-甲氧基-6'-((S)-2-甲基哌【口井】-1-基)-3,3'-聯吡啶-6-胺的其它鹽。
