<p>This study presents a finite difference-based analysis of the cone penetration test (CPT) in unsaturated silt. Both the extended Mohr–Coulomb model (MCM) and the Sun model (SM) were used to capture the unsaturated behavior of silts. A comparison was made between the capabilities of SM and MCM in predicting cone tip resistance in unsaturated silts. The distributions of the mean effective stress and degree of saturation, as well as the size of the plastic zone in soils (with different suctions) surrounding the cone, were investigated. Sensitivity analyses were performed to assess the influence of various SM parameters on the tip resistance. By performing a large number of numerical analyses of CPT with various SM parameters, a database of CPT results in unsaturated silt was established. This database was then used in nonlinear regression analysis to establish a correlation between tip resistance and unsaturated soil properties. Finally, the capability and accuracy of the developed relationship in predicting cone tip resistance in saturated and unsaturated silt was demonstrated by comparison with the results of previous studies.</p>