A dynamic flow-through chamber system and continuous analyzers were used for on-site measurements of ammonia-nitrogen (NH 3 -N) and hydrogen sulfide-sulfur (H 2 S-S) fluxes from commercial feedlot surfaces in northwestern Texas during two week period in the summer of 2002. Ambient air and air inside chamber temperatures, and manure pack temperature were measured continuously. Manure pack moisture content, pH, and TKN were measured daily to characterize its correlation with NH 3 -N fluxes. The preliminary average NH 3 -N flux from the feedlot surface for the entire measurement period was 1,669 ± 1,212 NH 3 -N µ g/m 2 /min (or 1,494 ± 1,083 NH 3 -N µ g/m 2 /min without accounting for the losses due to adsorption to chamber walls). Preliminary mean H 2 S-S flux was estimated at approximately at 1.884 ± 1.497 H 2 S-S µ g S/m 2 /min (1.683 ± 1.334 H 2 S-S µ g S/m 2 /min excluding the loss due to adsorption). Manure pack temperature was found to have a weak (R 2 = 0.492) logarithmic relationship with NH 3 -N flux (Log 10 NH 3 -N flux ( µ g N/m 2 /min) = 0.1308 × T soil ( o C) + 28.198). The TKN showed a weak (R 2 = 0.472) positive linear correlation with NH 3 -N flux.