Theoretical and experimental analyses have been performed to examine the position resolution of a proportional counter with a 7-mu m diameter carbon fiber as a resistive anode, which is used to encode one-dimensional positions of incident photons according to the charge-division method. These analyses have clearly shown that the carbon fiber is applicable to the position sensing of the order of 100-200 mu m as long as the filled gas is pressurized at near 10 atm. (C) 2000 Elsevier Science Ltd. All rights reserved.