Abstract: Great progresses have been made in the research of plant stress-resistance, but which signal transduction pathways are activated responding to environment stimulation are still unknown. Some researches have found out that many stimuli have something to do with Ca2+ and calmodulin. Ca2+ signal system is a very important transduction pathway, and calmodulin is the most important known r eceptor of intracellular Ca2+, which is involved in regulation of many physiological activities. Research workers have evidences in gene regulation level, transcription level, protein level that suggest Ca2+ and calmodulin are involved in heat shock reaction. Other environment stimulations also can lead to a series of changes of Ca2+ and calmodulin. These provide the foundation and basis for studying the probable signal transduction pathways of nvironment stimulation.