The positions of sampling sites in soil survey are vital to ensure the representativeness and reliability of the study results. The rapid development of 3S and internet techniques enable us to predesign sampling points indoors. There are many factors that may affect the accessibility of sampling points, but so far less or no information is available on this issue. In this paper, the field soil survey conducted in 2012 and 2013 in the Heihe River Basin in northwest China was taken as the example to investigate the accessibility of predesigned sample points and the influential factors, and then the effective countermeasures to improve the accessibility of sample points were proposed. The results showed that the accessibility of sample points usually was higher in the regions with relative flat terrain, intensive human activity and convenient traffic condition than these with undulate terrain, less human activity and poor traffic condition. Different effective measures should be taken for different regions to improve the accessibility of the sample points because the influential factors on accessibility of the sample points varied with studied regions.