Semantic-phonetic compounds comprise the vast bulk of the Chinese characters. The semantic radicals are related with the meaning of the whole characters, but inferring the whole characters’ meaning from semantic radicals’ meaning is not always applicable widely. There are almost 200 semantic radicals commonly to be used, the accuracy rate of inferring the whole character’s meaning by virtue of semantic radicals can be up to 60%-100%. The consistency of semantic radicals is one of the important characteristics of Chinese character’s radicals, which manifests the degree from semantic radicals’ meaning inferring the whole characters’ category. Previous studies have revealed that semantic radicals’ consistency affects the whole characters’ processing under many tasks and levels, including lexical decision, single-word semantic category decision and double words semantic category decision. Most of the studies concerned the adults’ mental lexicon and processing models. The developmental characteristics of children’ semantic consistency awareness has not been concerned yet. The present study was to examine children’s semantic radicals’ developmental characteristics. A total of 99 elementary school students were adopted in the study. Two factors mixed design were used: 4(Grade: Grade3, Grade 4, Grade 5, Grade 6)×4(priming style: R+S+,R+S-,R-S+,R-S-). Children were asked to judge the semantic category consistency between prime words and target words fast and accurately. The materials included 128 word stimulus pairs, each priming style has 32 word stimulus pairs. The results revealed a significant grade differences, a priming style differences and significant interaction between the grade and the priming style on reaction time and error rate. The reaction time got shorter and the error rate got reduced with the development of grades. Children in different grades showed different performance under four priming style. For children in Grade 3, there is no significant difference among four priming styles on reaction time. For children in Grade 4, the reaction time of R-S+ and R-S- were shorter than R+S- significantly. For children in Grade 5, the reaction time of R+S+ and R-S- were shorter than R+S- significantly. For children in Grade 6, the reaction time of R+S+ was shorter than R+S- and R-S+, also, the reaction time of R-S- was shorter than R+S- and R-S+. The tendency of error rate on consistency judgments showed similar performance. We also get a clear semantic consistency awareness priming effect by calculating the reaction time difference between two priming condition. Based on above findings, the conclusions could be derived from this study: (1) Children’s awareness of semantic radicals was getting strong with the development of grades. Children in Grade 3 have not acquired the consistency awareness of semantic radicals, children in Grade 4 have acquired preliminary consistency awareness of semantic radicals, Children in Grade 5 have made great process in consistency awareness of semantic radicals, children don’t have acquire mature semantic radicals’ awareness until Grade 6. (2) The developmental characteristics of semantic radical’ awareness has a close relationship with cognitive developmental level of children, language knowledge of children and processing strategy. Semantic radicals’ consistency should be taught intentionally.