The Zechstein petroleum system in the Polish part of the SPB stands out for the following characteristics: (i) source rocks reveal poor to fair oil-source potential, but ocally it is very good to excellent, (ii) the best reservoir rocks were on slopes and carbonate platforms, (iii) reconstruction of petroleum processes showed that the initiated of generation and expulsion took place in early Triassic and finished in the late Jurassic time, (iv) migration and accumulation of hydrocarbons was held in the same time as processes of generation and expulsion, (v) critical moment for this petroleum system which is connected with the main phase of generation and migration is dated for the beginning of the middle Triassic, (vi) on the part of area the critical point is located in the beginning of Neogene (after Laramian inversion).