In this letter, a machine learning (ML) model is presented to predict the variation of the threshold voltage (V_th) according to the taper angle and target word line (WLT) position in 3D NAND flash memory. Through Technology Computer-Aided Design (TCAD) simulation, V_th is extracted according to taper angle and WLT position. TCAD data is used as the training data set required for learning by an artificial neural network algorithm (NNA). The completed ML model is then used to predict V_th for each word line (WL). It was also confirmed that the ML model predicted well even for TCAD data that was not used as a training data set.