Abstract: 【Objective】Variety accreditation acts as the permiting for commercialization of maize varieties, the basis for the regulation and administration of seeds market, and the reference for variety selection and right protection in China. Therefore, comprehensive analysis on accredited maize varieties according to demands of businesses such as maize variety management, and in-depth exploration of the internal link and implicit message of these variety data can provide more systematic and distinct reference to seeds management departments, scientific research institutions, seeds enterprises and farmers.【Method】 The state and provincial authorized maize variety data of China in 42 years were obtained through material search, collection and data verification, and the trend of change of maize varieties on the market in different years and regions, the repeated rate of parental inbred lines of all the accredited maize varieties and the relationship between the accreditation, protection and withdraw from promotion of maize varieties were discussed.【Result】It is shown that during the period of 1972-2013, the total number of state and provincial accredited maize varieties was 6291, among which 503 were of state level, while the present state and provincial accredited variety number was 4882, among which 332 were of state level. A total of 1726 breeding organizations have records of accredited maize varieties, and scientific research institutions and seeds enterprises accounted for 48.3% and 46.6%, respectively, with an average of 7 and 3 varieties for each organization. A total of 8754 different parental inbred lines have been used in hybridization match of all accredited maize varieties, 19.4% of which were used repeatedly. The three most frequently used inbred lines were Mo17, Chang7-2 and Dan340. A record count of 1876 of all accredited maize varieties in 42 years have been withdrawn from promotion and the average employment period of such withdrawn varieties was 13.3a. Applications for new variety property have been filed for 29.2% of all accredited maize varieties in history and approved for only 15.1% of them.【Conclusion】During the recent 10 years, the number of accredited maize varieties at all levels increased steadily year by year, so was the maize variety inventory. In terms of trend, the northern area has more accredited varieties than the southern area and the number of accredited varieties in the eastern area increased faster than that in the western area. Of all breeding organizations, scientific research institutions acted as the main entity in terms of the quantity of accredited maize varieties and the number of accredited maize varieties of large-scale seeds enterprises increased remarkably. The number of newly-named parental inbred lines has increased rapidly, so the repeating rate of them has decreased year by year. The yearly number of accredited varieties withdrawn from promotion tends to be steady and fewer varieties are overlapped in both accreditation and property applications.

Key words: maize, variety accreditation, breeding organization, parental combination, varieties out of promotion, new variety property