The goals of this study are to compare different gene expressions for Penicillium oxalicum wild type strain (WT), and Podot1 knockout strain (?Podot1) in different carbon sources. The deletion of Podot1 downregulated genes involved in the septin complex, extracellular region, and interspecies interaction between organisms when strains were cultivated with 2% glucose as carbon sources, and downregulated genes involved in cellulase activity, cellulose binding, glucosidase activity, and polysaccharide catabolic process when strains were cultivated with 1% microcrystalline cellulose and 1% wheat bran as carbon sources. We find the extracellular region was downregulated under both different carbon sources in ?Podot1. This study provides the information that PoDot1 function are required in mycelial development and hydrolase activity of P. oxalicum. Overall design: Examination of differential gene expressions by digital gene expression tag profiling in Penicillium oxalicum wild type strain and Podot1 knockout mutant strains in 24h in modifeid Mendal’s medium with 2% glucose or 1% cellulose and 1% wheat bran as carbon sources.Three replicates were included for each samples.