Crystallization methods with self-assembled monolayers or Langmuir monolayers that provide templates are called templated crystallization. Various interesting phenomena were reported in templated crystallization. Crystallization at the template interface has been investigated from a phenomenological perspective in previous studies. However, in order to develop industrial applications of templated crystallization, understanding the phenomena at the template interface is necessary. The objectives of this present study are investigation of the change in morphology of crystals at the template interface with elapsed time and elucidation of the mechanism of the morphology change. The glycine (crystalline substance)-L-leucine (template compound)-water system was used. Glycine crystalline particles were crystallized at the template interface, that is, the air-solution interface with L-leucine. Lengths along the crystallographic a axis and c axis of the crystals were measured by using microscope images. From the calculation results of the growth rate ratio, it was understood that the change in crystal morphology was the decrease in the growth rate ratio with time elapsed. In order to estimate the mechanism of the decrease in the growth rate ratio, the effect of the repulsive force was considered. According to these results, the mechanism of the change in crystal morphology was the correlation between the growth rate ratio and the normalized clearance between the crystals at the template interface.