This paper contains evaluated chemical kinetic data on single step elementary reactions involving small polyatomic molecules which are of importance in propellant combustion. The work consists of the collection and evaluation of mechanistic and rate information and the use of various methods for the extrapolation and estimation of rate data where information does not exist. The conditions covered range from 500-2500 K and 10(17)-10(22) particles cm-3. The results of the second year's effort add to the existing data base reactions involving CN, NCO and HNCO with each other and the following species: H, H-2, H2O, O, OH, HCHO, CHO, CO, NO, NO2, HNO, HNO2, HCN, and N2O.