With methods such as polarizing and fluorescence microscope observation, homogeneous temperature and ice point temperature measurement and analysis of composition, a systematic study is conducted to acquire petrographic, salinity and homogenization temperature of fluid inclusions from Majiagou Formation of Yichuan-Huangling area in the Ordos basin. Finally, it can be inferredthat fluid inclusion of Majiagou Formation can be divided into two stages. The occurrence of bitumen inclusion demonstrates that paleo-oil reservoir may be once reconstructed. Besides, paleo-oil and-gas reservoir formation should be in early Jurassic-middle Jurassic and early Cretaceous respectively.