Аннотация:Type Ia Supernovae (SNe Ia) are widely used to measure the expansion of the Universe. Toperform such measurements the luminosity and cosmological redshift of the SNe Ia have to bedetermined. The luminosity can be measured thanks to so-called standardization procedure thatallows to correlate a luminosity of a supernova with its light curve or spectrum parameters. Unfor-tunately, even after the standardization procedures there is a remaining dispersion on the Hubblediagram. This dispersion can be due to environmental effects (age, chemical composition, dustaround a SN) which are not yet taken into account. Besides the standardization of SN Ia, theHubble diagram contains another parameter, i.e. the supernova cosmological redshift. In fact theredshift observed on the Earth is also affected by peculiar velocities. The exact contribution ofpeculiar velocities in the observed redshift is unknown, however it was shown that the peculiarvelocities have an impact on the distance measurements and therefore can potentially affect thecosmological analysis. Here, we discuss the impact of SN environment and peculiar velocities onthe distance measurements and cosmology. In the epoch of large transient surveys, developmentof observational techniques and further processing of the data, a study of any possible sources ofsystematical uncertainties in the cosmological analysis is of high priority.