A method to represent and measure personal knowledge stocks is proposed in the paper. Based on the analysis of the structure of personal knowledge stocks， a weighted knowledge network model is presented which can represent the structure of personal knowledge as a directed multi-tiered network， and can measure the personal knowledge stocks by valuing the weights of edges and the attributes of nodes. In the model the values of the node attributes denote how the knowledge points are mastered by a person， and the edges can indicate how the knowledge points are composed. The method to acquire and measure knowledge points is also proposed in the paper. In the end a case study is given.