Provided is a technique that makes it possible to store plasmalogen stably over an extended period of time. More specifically, provided is a plasmalogen-containing solid composition, etc., that contains plasmalogen, [gamma]-cyclodextrin, and a pH alkali adjuster, the plasmalogen-containing solid composition, etc., having a pH of 6-8 when made into a 1% by mass aqueous suspension.本發明提供一種可穩定地長期保存縮醛磷脂之方法。更具體而言,提供一種含有縮醛磷脂之固體組成物,含有縮醛磷脂、γ-環糊精、及pH鹼調整劑;作成1質量%之水懸浮液時的pH為6~8。