In this Letter, we theoretically analyze gaseous flow in a droplet train apparatus, which has been extensively utilized to study mass accommodation processes through gas/liquid interfaces. We numerically evaluate gas-phase resistance for uptake of trace gas into the droplets, via the coupled diffusion equation and fluid dynamics. In the results, gaseous resistance shows systematic deviation from values estimated from the ideal model with static spherical boundary conditions, indicating generation of additional resistance by interference among the train of droplets. Improved description of gas-phase resistance with optimized parameters in the flow tube is provided. (C) 2002 Elsevier Science B.V. All rights reserved.