The primary interests in our laboratory are to develop the basic knowledge and global understanding of the mechanisms and dynamics of elementary chemical reactions that have major impact on combustion and atmospheric chemistry. The main objectives are to determine the structure and chemical behavior of free radicals, and to provide microscopic details of primary photodissociation and bimolecular reaction processes. These objectives are achieved with a range of versatile experimental approaches using advanced molecular beam and laser technologies. Crossed molecular beam techniques based on electron impact ionization, VUV photo-ionization and H atom Rydberg "tagging" methods are the primary tools in our laboratory. By using these experimental techniques, fundamental information can be obtained on primary chemical reaction pathways and their mechanisms, product angular distributions, product translational and internal energy distributions etc. From these experimental results, detailed information on potential energy surfaces for chemical reactions can be derived. This will eventually help us to better understand and possibly solve the problems in atmospheric chemistry and combustion processes.