“…The study of the existence of mild solution for an integro-differential equation description is as follows: Recently, the fractional order differential equation model is more interesting and more descriptive to be applied in various branches such as engineering and science. So, the abstract Cauchy problems with fractional order derivative simulated to some problems of the fractional differential equation have appeared in many articles for many applications in real life (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Consider the following fractional order integropartial differential equations: where 1 , 2 , > 0, ( , ) is denoted the deviation x at , 1 < ≤ 2, 1 < 1 + 2 ≤ 2 and 0 < 1 , 2 ≤ 1, ≥ 0, and is a Riemann-Liouville fractional derivative of order > 0, ∈ (X is a Banach space).…”