Abstract: According to PDP theory, we tried to use a calculating model based on distributed representation to complete the task of case role assignment of Chinese sentences by parallel processing. There were six types of sentences.The model was a four-layer forward neural network: In input layer, we used distributed representaton to collect syntactic,semantic information(of the word in Chinese sentence) and context information,and there were two hidden layers, and output layer(case role layer). One part of the first hidden layer was feedback to the input layer. Error back propagation learning algorithm Was used to adjust three weight matrices sequently according to learning samples and target output in order to get correct answers When the network was stable, After training, the network was somewhat robust. In addition, the neural network method and the traditional symbol processing method used in natural language understanding was compared and analyzed.

Key words: neural network, weight, error back-propagation algorithm, case role