Thioredoxin reductase, together with thioredoxin and NADPH, is one of the components of thioredoxin system. Thioredoxin system is important in many biological activities, including ROS detoxification, transcription regulation and DNA synthesis. Thioredoxin reductase use NADPH as electron donor to reduce oxidized thioredoxin. There are two thioredoxin reductases, trxr-1 and trxr-2, in C. elegans. Both proteins are highly conserved through evolution and show high similarity compare to human homologues. The trxr-1 is mainly expressed in post pharyngeal bulb, vulva and post intestine, whereas trxr-2 is mainly expressed in posterior and anterior part of intestine. Both trxr-1 and trxr-2 mutants were obtained, and double mutants were generated. The expression levels of GFP fusion were increased upon heat shock and oxidative stress indicating that these genes are involved in stress response. Life span analysis at 25°C revealed that trxr-2 mutant had a shorter life span than wild type. These results suggest that trxr-2 have important function in stress response and life span regulation in C. elegans.