YMn1.07O3 ceramics were prepared by a sol–gel method, and the effect of Mn-excess on structure and dielectric properties was investigated. The X-ray diffraction pattern (XRD) shows that the sample has the hexagonal structure with space group P63cm. It is found to suppresses ferroelectric ordering and enhance antiferromagnetic ordering compared with YMnO3. Moreover, two dielectric relaxations were observed for the low and high temperature relaxations, respectively, which are considered to be associated with local dipole moments and the oxygen vacancies.