Modeling objects of traditional Verhulst model are only suitable for real number sequences. Therefore, an
expanding study of Verhulst model is given. Firstly, the axiom of grey degree not-reducing is expanded, and the conclusion
of information field not-reducing is obtained. Then a Verhulst model based on the kernel sequence of interval grey numbers
is obtained. On the foundation of the conclusion of information field not-reducing, this paper deduces the time response
formulas of lower limit point and upper limit point of interval grey numbers through the centers of kernels of interval grey
numbers. Finally, an example demonstrates the calculation process of the new model. Then proposed model has a vital
significance for enriching and perfecting the grey prediction model theory system, and extending the applied scope of grey
prediction model..