A microhollow cathode discharge (MHCD) was investigated by means of a fluid mode l. A highpressure He gas discharge for a cylindrical cathode was used in the model. The distribution of the electric field, electrons, ions and electron e nerg y has been calculated. The results show that there exists a hollow cathode disch arge ef fect in the discharge process. There existed electrons with high energy, and the electric field was mainly a radial field close to the cathode in the discharge area. The influ ences of gas pressure and dimension of the cathode on discharge characteristics were also investigated. We found that reducing the dimension of the cathode can enhance the hollow cathode effect, and increasing pressure will shorten the catho de fall.