Oxygen permeability is the most commonly used as gas permeability for contact lens materials,whether it does survey accurately or not directly affects the user’s vision health and comfort.In this paper,firstly we described the measurement principle of coulometric method,and then improved and applied the coulometric method on the measurement of oxygen permeability for rigid contact lenses.With experiments it was proved that the method was be feasible and stable.Finally,we analyzed the metrological motheds of permeability for rigid contact lenses and     proposed the expectation on how to realize its traceability.By settling the metrological calibration and establishing the transfer and traceability system for oxygen permeability of contact lenses,we are able to protect the consumer and improve the contact lens quality.