Abstract: The propagation of Jovian electrons depends on the spiral magnetic field in the interplanetary space. In this paper, the convection-diffusion equation for the Jovian electron transport is derived by using a new "spiral coordinate system", which is based on the interplanetary spiral magnetic field configuration, and a new model of Jovian electrons transport in the interplanetary space and the modulation of Jovian electrons in the orbit of the earth, which involves that of the Jupiter's synodic orbital period and the period of 27-day variations, is presented. The calculated results are coincident with the observations.