A slow positron beam line based on the 1.3 GeV linac of Beijing Electron-Positron Collider (BEPC) has been designed and constructed aiming to produce intense slow positron beam. By measuring the integral voltage of 0.511 MeV radiations using a home-made Pilot-U scintillation detector, a slow positron beam with intensity of 6x10(5) e(+)/s and energy spread of less than 10 eV (FWHM) was identified before the penning trap section. With the finish of BEPC improvement project, the positron beam intensity could reach 10(8) e(+)/s and the pulsing system for positron lifetime measurement is under construction.