Galoitica: Journal of Mathematical Structures and Applications GJMSA 2834-5568 10.54216/GJSMA https://www.americaspg.com/journals/show/1635 2022 2022 Cairo University, Cairo, Egypt Arwa Hajjari   The aim of this paper is to study the asymptotic behaviour of the following non-linear third order differential equations in large scale of time    〖〖〖[|u〗^(ˊˊ) (t)|〗^(p-1) u^(ˊˊ) (t)]〗^ˊ+f(t,u(t),u^ˊ (t),u^(ˊˊ) (t)=0    ;p≥1      (1).   Many results about this behavior will be presented and discussed in terms of theorems, as well as many related examples will be illustrated.     2023 2023 08 14 10.54216/GJMSA.040101 https://www.americaspg.com/articleinfo/33/show/1635