8A number of numerical simulations and experimental investigations have reported the impact of 9 specific domain size on the dynamic capillary pressure which is one of the forces that govern two-10 phase flow in porous media. These investigations are often achieved with time-consuming 11 experiments and/or costly/complex computational methods. In view of this, a computationally 12 efficient and simple alternative platform for the prediction of the domain scale dependence of the 13 dynamic capillary pressure effects, defined in terms of a coefficient named as dynamic coefficient ( 14 τ ), is developed using artificial neural network (ANN). The input parameters consist of the phase 15 saturation, media permeability, capillary entry pressure, viscosity ratio, density ratio, temperature, 16 pore size distribution index, porosity and domain volume with corresponding output τ obtained at 17 different domain scales. Good generalization of the model was achieved by acquiring data from 18 independent sources comprising experiments and numerical simulations. Different ANN 19 configurations as well as linear and non-linear multivariate regression models were tested using a 20 number of performance criteria. Findings in this work showed that the ANN structures with two 21 hidden layers perform better than those with single hidden layer. In particular, the ANN configuration 22 with 13 and 15 neurons in the first and second hidden layers, respectively, performed the best. 23Using this best-performing ANN, effects of increased domain size were predicted for three separate 24 experimental results obtained from literature and our laboratory with different domain scales. 25Results showed increased magnitude of τ as the domain size increases for all the independent 26 experimental data considered. This work shows the applicability and techniques of using ANN in the 27 prediction of scale dependence of two-phase flow parameters. 28Keywords: Multi-scale, dynamic capillary pressure effects, dynamic coefficient, ANN, two-phase 29 flow, viscosity ratio, porous media 30