The relevance of the research is in studying the gases of the Southern Caspian section upper part, in particular its deep-water part, which is of significant practical interest when searching and estimating hydrocarbon potential of gas hydrate zones. The analysis of the works carried out within the South Caspian showed that all the studies are mainly concentrated within the drilled zone of Absheron, Baku and Nizhnyaya Kura oil and gas regions, and do not cover the deep-sea zone of the Southern Caspian. The aim of the research is to study hydrocarbon gases intensity distribution by area, as well as to determine gas generation zones. In addition, the work was carried out to determine and analyze hydrocarbon migration routes and types of formation of gas hydrates within the deep-sea zone of the Southern Caspian. The object of the researchwas 1282 gas samples selected in the South Caspian at Shah Deniz, Bakhar, Pirallahi, Khali, deep-water South Caspian, and other geological and geophysical data. The data on chemical and isotope composition of the hydrocarbon gases of the South Caspian basin were used on 147 gas samples taken from oil and gas fields, 153 samples from mud volcanoes, 29 samples from bottom sediments and 4 samples from gas hydrates. These data enabled more reasonable approach to the analysis of genetic issues of gases origin in the upper part of the section. Research methods are based on interpretation of gas survey data and investigation of isotope and chemical composition of hydrocarbon gases of the Southern Caspian. The presence of exact values of coordinates, as well as data on structural maps in the grid, enabled to compare the available data with the geological structure. Result. The authors have constructed the maps of the change in the content of methane, ethane, propane, butane, iso-, normal pentane within the upper part of the section for the studied deposits and compared the data of the results of the analysis of gas survey with the data of structural maps and other geological and geophysical material. It is established that the structure of the Bakhar is characterized by a relatively low intensity of methane gas reservoirs from 5,37•10^–4 to 152944•10^–4 % (average 9109,0354•10^–4 %), while the Shah Deniz field is characterized by the maximum values from 4,6200•10^–4 to 367,840•10^–4 %, an average of 85,572,3•10^–4 %. Small values of gas intensity, established in the zone of the structures of Pirallakhi, Khali, indicate insignificant gas potential of deep/seated deposits of the studied zone. The results of the gas survey within the deep-water part of the South Caspian were considered in detail and it was established that for this zone gas generation is typical, with the predominance of two components – methane and ethane. Based on the analysis of the change in the intensity of gas manifestations by area and depending on geological conditions it was established that mud volcanoes and faults are excellent ways for hydrocarbon migration and reflect the geological situation and the generation potential of the submerged deposits of the Southern Caspian. It was established that hydrocarbon gases in bottom sediments and sediments of the upper part of the South Caspian section are closely related to the sources of hydrocarbon formation, migration and other processes occurring in deeply buried sediments, as well as in upper part of the section. The authors studied the data of the chemical and isotopic composition of gas hydratesgases, oil and gas deposits of the South Caspian. Based on the data of isotope/geochemical studies the authors described the mechanisms of formation of giant oil deposits of Balakhany-Sabunchi-Romana and Shahdeniz gas condensate located on one anticlinal zone of the Absheron oil and gas bearing area, as well as anomalies revealed from gas survey data within the studied structures of the South Caspian.