This work aimed to study differential gene expression at transcriptional level of probiotics Lactobacillus casei Zhang growth under low temperature and low pH conditions. In this study， Lactobacillus casei Zhang was cultured in MRS liquid medium for three generations and grown under cold stress and low pH environments at 4 ℃. Samples were taken intermittently. Twelve Lactobacillus casei Zhang genes， including genes associated with carbohydrate metabolism， amino acid metabolism， cell membrane fatty acid， and stress protein were continuously monitored under the adverse growth condition by reverse transcription polymerase chain reaction（PCR）. The results showed that five genes were up-regulated under the adverse circumstances， including three genes related to glucose metabolism （NAD-dependent malic enzyme， glucose-6-phosphate1-dehydrogenase， UTP-glucose-1-phosphate uridylyltransferase）， one gene encoding a cell membrane fatty acid synthesis enzyme （cyclopropane fatty acid synthase）， and one gene encoding a stress protein （chaperonin Gro EL）. While the expression of seven genes was down-regulated， including the gene coding a DNA primase， three amino acid metabolism-related genes （cation transport ATPase， D-glutamic acid metabolism， ABC transporter ATP-binding protein）， two membrane fatty acid genes （phospholipid biosynthesis protein， short-chain alcohol dehydrogenase）， and PTS cellobiose-specific transporter subunit IIA. This work provides some references for analyzing the changes in physiological and biochemical characteristics， as well as stress resistance mechanism of Lactobacillus casei Zhang when grown under adverse growth condition.