The BP model of neural network was used to predict the release of insoluble drugs from HPMC matrix tablets in different mediums.Trimethoprim, carbamazepine, sulfamethoxazole and theophylline were selected as the poor soluble model drugs.The BP model of neural network with a math. formula was used to predict the drug release in the medium with different pH and ionic strength.The results showed that the math. model predicted the release effectively.The neural network could be used to precisely predict the release of insoluble drugs from HPMC matrix tablets in different medium.