An image capturing system lens assembly, comprising five lens elements (E1, E2, E3, E4, E5), the five lens elements (E1, E2, E3, E4, E5) 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 and a fifth lens element, each of the five lens elements (E1, E2, E3, E4, E5) has an object-side surface towards the object side and an image-side surface towards the image side; 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 fifth lens element comprises at least one inflection point; at least one of the first lens element to the fifth lens element is made of plastic material and has the object-side surface and the image-side surface being both aspheric; wherein the image capturing system lens assembly further comprises an aperture stop, an axial distance between the aperture stop and an image surface is SL, an axial distance between the object-side surface of the first lens element and the image surface is TL, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, a maximum among T12, T23, T34, T45 is ATmax, an axial distance between the image-side surface of the fifth lens element and the image surface is BL, a focal length of the image capturing system lens assembly is f, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a curvature radius of the object-side surface of the first lens element is R1, and the following conditions are satisfied: 0.75 < SL / TL < 1.50; 1.00 < TL / f < 5.00; and − 2.00 < f / f 3 < 0.85 characterized in that the following conditions are satisfied: 0.78 < ATmax / f < 9.00; 2.00 < ATmax / BL < 7.00; − 5.00 < f / R 1 < 0.45; and − 0.6 < f / f 2 < 3.00. a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, each of the five lens elements (E1, E2, E3, E4, E5) has an object-side surface towards the object side and an image-side surface towards the image side; 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 fifth lens element comprises at least one inflection point; at least one of the first lens element to the fifth lens element is made of plastic material and has the object-side surface and the image-side surface being both aspheric; wherein the image capturing system lens assembly further comprises an aperture stop, an axial distance between the aperture stop and an image surface is SL, an axial distance between the object-side surface of the first lens element and the image surface is TL, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, a maximum among T12, T23, T34, T45 is ATmax, an axial distance between the image-side surface of the fifth lens element and the image surface is BL, a focal length of the image capturing system lens assembly is f, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a curvature radius of the object-side surface of the first lens element is R1, and the following conditions are satisfied: 0.75 < SL / TL < 1.50; 1.00 < TL / f < 5.00; and − 2.00 < f / f 3 < 0.85