We study the birth and evolution of isolated neutron stars in the Milky Way with new population synthesis code. We model the birth of massive OB stars and follow their motion within the spiral arms up to the supernova explosion. After that we consider the evolution of NS up to the death line with taking into account the magnetic field decay. We find that significant magnetic field decay occurs during the first stages of a NS's life. Derived values of mean time of ohmic decay for NS is two hundred thousand years. To simulate the ensemble of the galactic pulsars we consider the different scenarios of the pulsar's radio luminosity. First of them is a standard flat cone model by Narayan & Ostriker (1990) with exponential energy distribution in the cone and the second is a spark model by Fan et al. (2001). To select the best of them we compare the distributions of pulsar periods (P), derivatives of periods (ṗ) and pulsar magnetic fields (B) with obtained from ATNF pulsar catalogue data. We conclude that the realis