Nonclassicality of optical states,as a key characteristic of bosonic fields,is a valuable resource for quantum information processing.We investigate the generation of nonclassicality in quantum processes from a quantitative perspective,introduce three information-theoretic measures of nonclassicality for quantum-optical processes based on the Wigner-Yanase skew information and coherent states,and illustrate their physical significance through several well-known single-mode quantum processes.