An optical imaging system assembly comprising a total number of seven lens elements (E1, E2, E3, E4, E5, E6, E7), the seven lens elements (E1, E2, E3, E4, E5, E6, E7) being, in order from an object side to an image side along an optical path: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element; each of the seven lens elements (E1, E2, E3, E4, E5, E6, E7) has an object-side surface towards the object side and an image-side surface towards the image side; wherein the first lens element has positive refractive power, the object-side surface of the first lens element is convex in a paraxial region thereof, the image-side surface of the first lens element is concave in a paraxial region thereof; the second lens element has negative refractive power; the object-side surface of the third lens element is convex in a paraxial region thereof; the fifth lens element has positive refractive power; the sixth lens element has negative refractive power; and the seventh lens element has negative refractive power; wherein at least one of the object-side surface and the image-side surface of at least one of the first lens element to the seventh lens element comprises at least one inflection point; wherein an Abbe number of the fourth lens element is V4, an Abbe number of the fifth lens element is V5, an Abbe number of the sixth lens element is V6, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, a central thickness of the sixth lens element is CT6, an axial distance between the sixth lens element and the seventh lens element is T67, an f-number of the optical imaging system assembly is Fno, half of a maximum field of view of the optical imaging system assembly is HFOV, a focal length of the optical imaging system assembly is f, a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, a focal length of the seventh lens element is f7, a curvature radius of the object-side surface of the seventh lens element is R13, a curvature radius of the image-side surface of the seventh lens element is R14, and the following conditions are satisfied: 4.4 < V 5 + V 6 / V 4 < 12; 1.0 < CT 1 + CT 2 + CT 3 + CT 4 + CT 5 + CT 6 / T 67 < 3.5; 1.3 < Fno < 2.4; 35.0 degrees < HFOV < 50.0 degrees; f / f 3 + f / f 4 < 0.75; and − 1.2 < f 7 / R 13 + f 7 / R 14 < 0. a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element; each of the seven lens elements (E1, E2, E3, E4, E5, E6, E7) has an object-side surface towards the object side and an image-side surface towards the image side; wherein the first lens element has positive refractive power, the object-side surface of the first lens element is convex in a paraxial region thereof, the image-side surface of the first lens element is concave in a paraxial region thereof; the second lens element has negative refractive power; the object-side surface of the third lens element is convex in a paraxial region thereof; the fifth lens element has positive refractive power; the sixth lens element has negative refractive power; and the seventh lens element has negative refractive power; wherein at least one of the object-side surface and the image-side surface of at least one of the first lens element to the seventh lens element comprises at least one inflection point; wherein an Abbe number of the fourth lens element is V4, an Abbe number of the fifth lens element is V5, an Abbe number of the sixth lens element is V6, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, a central thickness of the sixth lens element is CT6, an axial distance between the sixth lens element and the seventh lens element is T67, an f-number of the optical imaging system assembly is Fno, half of a maximum field of view of the optical imaging system assembly is HFOV, a focal length of the optical imaging system assembly is f, a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, a focal length of the seventh lens element is f7, a curvature radius of the object-side surface of the seventh lens element is R13, a curvature radius of the image-side surface of the seventh lens element is R14, and the following conditions are satisfied: 4.4 < V 5 + V 6 / V 4 < 12; 1.0 < CT 1 + CT 2 + CT 3 + CT 4 + CT 5 + CT 6 / T 67 < 3.5; 1.3 < Fno < 2.4; 35.0 degrees < HFOV < 50.0 degrees; f / f 3 + f / f 4 < 0.75; and − 1.2 < f 7 / R 13 + f 7 / R 14 < 0.