PROBLEM TO BE SOLVED: To provide a crystalline form and a preparation method of perindopril arginine excellent in safety from the viewpoint of pharmaceutical value thereof.SOLUTION: There are provided a &delta；-crystalline form of an arginine salt of perindopril, its preparation process, and pharmaceutical composition containing the same. The crystalline form is represented by formula (I), and exhibits a characteristic powder X-ray diffraction as measured by a diffractometer having an anticathode of copper.【課題】ペリンドプリルアルギニンの薬学的価値の観点から、優れた安定性を有する結晶形態及び調整方法を提供する。【解決手段】ペリンドプリルのアルギニン塩のδ結晶形態、その調製方法、及びそれを含む医薬組成物。式（Ｉ）：で示され、結晶形態は、銅の対陰極を備えた回折計で測定され、その粉末Ｘ線回折表を特徴とする。【選択図】なし
