The present invention relates to a crystal form of 2-(6-methyl-pyridin-2-yl)-3-(6-amido-quinolin-4-yl)-5,6-dihydro-4h-pyrrolo[1,2-b]pyrazole (Galunisertib or LY2157299), represented by formula (I). Compared with the known solid form of Galunisertib, the crystal form of the present invention has advantages in terms of solubility, hygroscopicity, crystal stability, morphology and the like. The present invention also relates to a process of preparing the crystal forms of Galunisertib, a pharmaceutical composition thereof and a use thereof in the preparation of a medicament for the prevention and/or treatment of diseases associated with TGF-beta.