The invention relates to I-type crystallization of N-n-propyl-3-(4-methylphenyl)-4-(4-mesylphenyl)-2,5-dihydropyrrole-2-ketone and a manufacturing method thereof. The method comprises the step of crystallizing any crystal form of or amorphous N-n-propyl-3-(4-methylphenyl)-4-(4-mesylphenyl)-2,5-dihydropyrrole-2-ketone solid with a polar organic solvent or aqueous solution thereof to obtain the I-type crystallization of N-n-propyl-3-(4-methylphenyl)-4-(4-mesylphenyl)-2,5-dihydropyrrole-2-ketone. The obtained I-type crystallization of N-n-propyl-3-(4-methylphenyl)-4-(4-mesylphenyl)-2,5-dihydropyrrole-2-ketone has favorable crystal form stability and chemical stability, and the utilized crystallization solvent has low toxicity and less residue, thereby the invention can be better used for clinical treatment.
