... Line radiative transfer in C 18 O, HCO + , and CS lines is considered in a spherically symmetric chemo-dynamical model of a starless core, evolution of which is driven by the ambipolar diffusion. Theoretical line profiles are compared to observational data on the well-known L1544 core, which is one of possible candidates for collapsing protostellar clouds. ... Comparison between modelled and observed spectra suggests that L1544 has flattened structure and is observed at some inclination. ...