Compliance with distinctness, uniformity and stability requirements is a precondition for granting of plant breeder’s rights and variety registration. Similar varieties screening is a key technical step for distinctness test. In this study, charecteristics of 3696 varieties (incuding single cross hybrids and inbred lines) from Huang-huai-hai Region planted in 6491 plots from different years at a single location were observed and recorded according to maize DUS test guildlines. After data collation and conversion of mearurments into notes, a database composed of charateristics data of 3696 varietis was constructed. Based on the investigation of variation of observations of state of expressions for the characteristics, the range of notes for 27 charactristics was determined and the charateristics were classified into four classes accordingly. A similar variety screening method was developed based on the deternined range of notes for each charateristic using the characteristics database. This method improves the effciency and stringency of similar variety screening using phenotypic characteristics.