Several lines of evidences show that reactive oxygen species (ROS), taking H(2)O(2) considered, and the protein kinase, especially mitogen-activated protein kinase (MAP kinase), jointly regulated plant stress signaling. In plant cells, a number of MAP kinases were specifically involved in oxidative burst (OXB) or hypersensitive response (HR) in response to biotic stresses, besides salicylic acid (SA) induced MAP kinase (SIPK) and ROS play the crucial roles in the processes of systemic acquired resistance (SAR) being established. The reciprocal relationship between SIPK and ROS could be essential in response to abiotic stresses in plant cells, because it was indicated that ozone, wounding, or osmotic stimuli activated SIPK. Together, these primary results showed that MAP kinases were required for ROS signaling in response to stress in plant cells, and more studies are in demand in this area.