Optoelectrochemical method (OEM) as a combination of electrochemical and ellipsometric methods has been developed and used for quantitative approach of generalized description of surface state and electrocatalytic properties of smooth standardized and modified nickel electrodes in alkaline solutions. Two well-known principles are underlined the OEM: (1) insensitivity of ellipsometric method to hydrogen adsorption at least within the wavelengths interval 500-700 nm; (2) proportionality between changes in adsorbed oxygen amount and ellipsometric parameter Delta. Using OEM it has been succeeded to obtain the 'absolute' oxygen adsorption isotherm with respect to true surface area. On the base of this 'absolute' isotherm the simple method for true surface (roughness, R) determination has been proposed. First for he case of compact nickel the hydrogen adsorption and absorption isotherms and oxygen adsorption one have been obtained separately. By extrapolation of Delta,R dependence to R = 1 the metal optic constants n and k has been determined. The blocking behavior of different types of oxides has been investigated. The peculiar properties of amorphous layer produced by abrading treatment have been studied. It has been shown that this amorphous layer adsorbs much more hydrogen amount wit respect to true surface area than common one. The specific oxidation rate of hydrogen adsorbed on such a layer is also much higher.