Molecular dynamics simulation was performed to study the deformation behaviors of monoclinic zirconia substrate for three different indentation orientations and different load speed during indentation.The coordination number were adopted to analyze the atomic configuration of the substrate and the variation of dislocations in different indentation depths.The P-h curves and deformation behaviors for various indentation orientations were compared.Three types of slip planes are observed in m-ZrO2 for three different indentation orientations;The(100)plane and(100)plane indentation produce obvious pile-up and sink-in phenomena,respectively,and the response of indentation shows dis continuous fluctuations in their P-h curves.Comparison of the indentation results at three different velocity on(001)plane,reveals the significant influence of the stress relaxation on the strain hardening and load fluctuation at low loading velecity.