Abstract: Low pressure two dimensional position sensitive multiwire proportional chamber(MWPC) was developed to be used to study the nuclear reaction induced by radioactive ion beam. Each detector has a 50 mm×50 mm sensitive area and consists of three grids(x-position, cathode, y-position). The position was determined through delay line readout mode. The detectors have good beam transparency and are also adequate to be used in vacuum. The MWPC was tested at a pressure of 800 Pa of n-heptane and a bias voltage of 720 V. The test results indicate that two track position resolution of the chamber is Δx=Δy=1 mm and position determination efficiency is larger than 80% for the low Z particle at intermediate energies. This kind of chamber can be used to determine the (direction) of the incident particle and to detect the emitting angle of the reaction products.