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The VosA-VelB hetero-dimeric complex plays a pivotal role in regulating development and secondary metabolism in <i>Aspergillus nidulans</i>. In this work, we characterize a new VosA/VelB-activated gene called <i>vadH</i>, which is predicted to encode a 457-amino acid length protein containing four adjacent C₂H₂ zinc-finger domains. Mutational inactivation of <i>vosA</i> or <i>velB</i> led to reduced mRNA levels of <i>vadH</i> throughout the lifecycle, suggesting that VosA and VelB have a positive regulatory effect on the expression of <i>vadH</i>. The deletion of <i>vadH</i> resulted in decreased asexual development (conidiation) but elevated production of sexual fruiting bodies (cleistothecia), indicating that VadH balances asexual and sexual development in <i>A. nidulans</i>. Moreover, the <i>vadH</i> deletion mutant exhibited elevated susceptibility to hyperosmotic stress compared to wild type and showed elevated production of the mycotoxin sterigmatocystin (ST). Genome-wide expression analyses employing RNA-Seq have revealed that VadH is likely involved in regulating more genes and biological pathways in the developmental stages than those in the vegetative growth stage. The <i>brlA</i>, <i>abaA</i>, and <i>wetA</i> genes of the central regulatory pathway for conidiation are downregulated significantly in the <i>vadH</i> null mutant during asexual development. VadH also participates in regulating the genes, <i>mat2</i>, <i>ppgA</i> and <i>lsdA</i>, etc., related to sexual development, and some of the genes in the ST biosynthetic gene cluster. In summary, VadH is a putative transcription factor with four C₂H₂ finger domains and is involved in regulating asexual/sexual development, osmotic stress response, and ST production in <i>A. nidulans</i>.