It is mostly difficult to accurately understand the relation between source performance and near-surface structures in the regions, where complex surface, topography and/or near-surface conditions are present. In this study, we analyzed source performance and near-surface structures by using a crooked 2D seismic vibroseis dataset acquired in the area with complex topography, near-surface structures and various noises, onshore Japan. Two types of methods were exploited to evaluate source performance. One is a method proposed in a prior study, which uses middle-offset parts of shot data to calculate source performance from the absolute values of stack data. Another method presented by this paper utilizes the first arrival amplitude for near-offset parts of shot data to compensate the drawback of the first method, which is contaminated by background noise. Near-surface conditions are analyzed by 3D first arrival seismic tomography, which takes the effects of crooked line geometry and topography into account, and public borehole datasets. The comparison between the calculated source performance distributions and near-surface models shows that the regions with high P-wave velocity and stiff lithology are correlated with the regions which have relatively high-source performance. Hence, the above approach based on the two methods is capable of estimating the optimum locations to realize high-source performance even in onshore fields with complex topography and near-surface structures.