Abstract：In this paper， the effects of sigma factor and RNase on the expression of non-coding RNA ArpH in Salmonella enterica serovar Typhi(S. Typhi)were studied， and the effects of ArpH on bacterial invasiveness and intracellular viability were preliminarily studied based on the results of whole genome microarray. The effects of rpoE and rpoS on ArpH transcription and the degradation of ArpH by RNase III， RNase G and RNase E were detected by qRT-PCR. The effects of ArpH on the invasiveness and intracellular viability of S. Typhi were observed. In rpoE deletion strain， the expression level of ArpH decreased significantly under various stress conditions. In rpoS deletion strain， the expression level of ArpH decreased significantly under oxidative stress. The level of ArpH in Rnase III deletion strain was significantly higher than that in wild type strain， but there was no significant difference in RNase G deletion strain or RNase E deletion strain. RNase III mightbe the main endoribonuclease of ArpH. After overexpression of ArpH under oxidative stress， 89 genes were up-regulated and 24 genes were down-regulated. ArpH is ableto weaken the invasive capacity of S. Typhi to HeLa epithelial cells and enhance the intracellular survival of S. Typhi in THP-1 cells.