This study investigated the process by which the representational activity and knowledge about drawing and letter and number writing emerge in children 21-46 months old. The results revealed that representational activities developed with age through several phases. Beginning at age 2, children produced different marks for different systems, but children under two produced common graphic marks. Representational systems were significantly correlated with developmental processes, but drawing developed faster than letters or numbers with respect to both their production and their classification. Three-year-old children were able to recognize each system correctly in a sample-matching task, but the recognition of each system was not correlated with representational activity. These findings indicate that only after children engaged in graphic production did they begin to make representational distinctions among systems by drawing on their domain-specific knowledge, although alternative explanations can be suggested.