Аннотация:The work is devoted to obtaining explicit formulas for analytic continuation of a quite general class of hypergeometric series with three variables. Such formulas have been constructed for continuation with respect to one variable for an arbitrary series belonging to the class under consideration. In addition, on the base of several examples we have demonstrated the use of the obtained formulas for construction of analytic continuation with respect to all three variables. The obtained continuation formulas give representations for triple hypergeometric series outside the domain of their convergence in the form of combinations of other hypergeometric series that belong to the Horn class and are solutions to the same system of partial differential equations. The results of the paper are useful for qualitative analysis and calculation of triple hypergeometric functions.