A study has been made of the influence of hydrogen on the conversion of a mixture of C-2-C-4 hydrocarbon gases into liquid C-5-C-12 hydrocarbons on an SGK-1 zeolite-containing catalyst modified with chromium under oligomerization conditions (t = 350 degrees C). It has been established that the presence of hydrogen in C-2-C-4 gases has a positive effect on the production of C-5-C-10 aliphatic hydrocarbons and increases the period of active operation of a zeolite-containing catalyst between regenerations.