In geophysics, the term seismic tomography is known for a long time. This is due to the fact that one of the main problems in seismology – the inverse kinematics. It consists in determining the velocity structure at a known time path of the refracted waves from source to receiver. The most popular in engineering geophysics was crosshole Seismotomography. This direction is used for detailed studies of rocks velocity structure in the interborehole space.ZondST2d represents ready solution for seismic tomography, and solves wide range of problems from mathematical modeling and quality control to field data processing and interpretation. Convenient interface and variety of data visualization features allow to solve wide range of geological problems with maximum effectiveness. first arrivals times picking. Special attention is paid to variety ways of data visualization and simple access to frequently used functions. mathematical modeling of velocity structure for seismic tomography survey. Modeling gives a chance to estimate the level of reflected waves first times and to make a choice of optimum parameters of the observation system for decision of formulated geological problem. ZondSt2d has great range of tools for mathematical modeling and analysis of refracted and reflected waves. Standard mesh “bitmap” style, arbitrary layered model and polygonal style model. Additional tools for gravity, magnetic forward modeling and for joint inversion(Vp&VS, MASW, reflection and refraction, TDEM, VES, gravity and magnetic). • Number of the inversion algorithms : smooth, focusing, robust, block. Setting the reference model for the inversion. Suppressing of the noise component during inversion (robust reweigthing). • Suppressing static shifts during inversion. • Setting of limits for models parameters, inserting of a priori geological boundaries and borehole data to inversion. Assignment of weights for datum records. Editor of measurements. • Estimation of results quality based on sensitivity matrix analysis. Calculation of sensitivity, quality and DOI index. • Number of variants for data, model and apriori information visualization. Ability to set a semitransparent background for the resistivity section (geological, seismic sections). • Three-dimensional visualization of the velocity sections along arbitrary system profiles. Maps slices of parameters for various depths. • Geological sections editor and borehole columns editor. Titled boreholes. • Exporting to bitmap and vector graphics formats, excel, surfer, AUTOCAD. Setting the scale of the exported image. Print images and create reports.