Biodiesel is a mixture of long chain fatty acid methyl esters used mainly in compression ignition engines. In order to improve engine performance, an understanding of its fundamental properties and the combustion pathways is required. A surrogate fuel: methyl decanoate (MD) is used in order to simplify the models and experiments. This study presents new data for MD combustion in a laminar counterflow premixed flame configuration (spray MD/air against methane/air) at atmospheric pressure, for different strain rate and equivalence ratio conditions. The visible and UV chemiluminescence of the excited radicals CH* (A2Δ) and OH* (A 2Σ+) as well as Planar Laser-Induced Fluorescence (PLIF) of OH are employed experimentally to analyze the flame structure. The counterflow spray flame is simulated by choosing a MD skeletal reaction mechanism, to which we add CH* and OH* reactions. The numerical predictions of the CH* concentration are very close to the experimental profiles along the central axis. The numerical and experimental results indicate differences in the OH* production routes between MD and methane flames.