The present invention, pyrazolo - co-crystal with respect to a novel co-crystal former and pyrimidines, organic carboxylic acid, the co-crystal former is selected from the group of the xinafoate gentisic acid, and succinic acid. [Formula 1]本発明は、ピラゾロ-ピリミジン類と共結晶形成剤の新規な共結晶に関し、この共結晶形成剤は有機カルボン酸、好ましくはゲンチシン酸、コハク酸およびキシナホ酸の群より選択される。【化1】