Tissue-equivalent proportional counter (TEPC) is a very promising dosemeter for radiation protection in mixed radiation fields. In this article, a portable TEPC system including a spherical homemade TEPC detector and the compact low-power integrated circuit prototype was constructed and tested in gamma and neutron radiation fields. The microdosimetric spectra results displayed that the portable TEPC system could deal with four orders of magnitude voltage pulse signals. And the measured dose equivalent values agreed with reference values, which means the portable TEPC system had fulfilled the test and satisfied the requirement for radiation monitor.