The present disclosure provides a method for imaging a compound contained by a lipid vesicle in water. The method comprises the following steps of: (a) providing an aqueous sample comprising the lipid vesicle which contains the compound, wherein the aqueous sample further comprises ammonium sulphate ((NH4)2SO4)； (b) illuminating the aqueous sample with an X-ray free-electron laser (X-FEL)； (c) with an image sensor, collecting a plurality of coherent diffraction image patterns of the aqueous sample being illuminated； and (d) reconstructing the coherent diffraction image patterns with a computer such that an image of the lipid vesicle containing the compound is acquired. A method for examining a quality of a chemical drug contained by a liposome in water is also provided.
