Before revision:  To dissolve such risks , we propose  a hybrid feature representation, which is feeded into a gradient boosting model for credit risk assessment of guarantee network.
After revision:  To dissolve such risks , we propose an imbalanced network risk diffusion model to forecast the enterprise default risk in a short future. Positive weighted k-nearest neighbors (p-wkNN) algorithm is developed for the stand-alone case -- when there is no default contagious; then a data-driven default diffusion model is integrated to further improve the prediction accuracy. We perform the empirical study on a hybrid feature representation, which is feeded into a gradient boosting model for credit risk assessment of guarantee network.