It is known that the tooth flank geometry, assembly errors and the operating conditions of a gear pair have significant influence on tooth contact, load distribution and dynamic response. However, the study of the effects of assembly errors on the mesh characteristics and dynamic response for crossed beveloid gears has been limited due to the complicated geometry and time-varying mesh characteristics. In this study, three types of assembly errors including shaft angle, offset and gear axial position error are examined based on a synthesized mesh model and a three-dimensional elastically coupled rigidbody dynamic model. Also, the relation between a dominant geometry design parameter that is the crossed angle between the first principal directions of the tooth surface curvatures (FPD-angle) and the sensitivity of mesh characteristics and dynamic response subject to assembly errors is investigated. Through the sensitivity analysis with different FPD-angles, the shaft angle error is found to be the most sensitive factor affecting the mesh and dynamic behaviors of crossed beveloid gear set. On the other hand, the gear axial position errors have the least influence on the mesh characteristics and dynamic response. In most cases, the influences of assembly errors on mesh characteristics and dynamics become weaker with the increase of FPD-angle.