The optical transmission matrix method was presented based on the tuning characteristics of three kinds of micro-resonators of one-dimensional photonic crystals with defects,in which two resonators are surrounded by high refractive index materials and one is surrounded by low refractive index materials.For normal incidence wave with a certain wavelength in each structure,a field with larger amplitude than that of the incident wave field is found in the defect layer,i.e.,resonance occurs and a micro-resonator is formed.The resonance wavelengths increase nonlinearly with the thickness of the defect layer for the structures 1 and 2 in which the defect layer is surrounded by high reractive index materials,and linearly for the structure 3 in which the defect layer is surrounded by low refractive index materials.For single mode operation,however,the relative tuning range for structures 1 and 2 is about 3 times of structure 3.