Microlejeunea ulicina is one of the leafy liverworts species found in Universitas of Indonesia that has unique characteristics and its existence in Java Island has not been reported before. The ultrastructure analysis of Microlejeunea ulicina is important not only as the mean of identification but also for further exploration of their oil body which contains useful metabolites. Ultrastructure investigation can be accomplished by using Scanning Electron Microscopy (SEM). However, the optimization of the preparation steps for biological sample observation by SEM, including liverworts, is necessary to be carried out. Drying step plays the important role in maintaining the structure of the sample as close-to-native as possible. Thus, the aim of this study is to evaluate the effect of the drying step in the preparation of Microlejeunea ulicina for SEM observation. Microlejeunea ulicina were fixed with 2.5% glutaraldehyde, post-fixed with 4% osmium tetroxide, dehydrated with ethanol series, and then subjected to different drying method, i.e. air-drying and freeze-drying. According to the data obtained, samples dried by using freeze-drying method showed the more detailed structure in conjunction with the up-and-down contour, without any artefact covering the surface of the samples, while air-dried samples showed the flat surface hiding the real structure of the cell. Our data suggested the advantages of freeze-drying in preparing Microlejeunea ulicina for ultrastructure investigation using SEM. The results of this study can further be applied as the basic procedure for other biological samples observation by using SEM.