  In this paper, we study the global well-posedness and scattering of 3D
defocusing, cubic Schr\"odinger equation. Recently, Dodson [arXiv:2004.09618]
studied the global well-posedness in a critical Sobolev space
$\dot{W}^{11/7,7/6}$. In this paper, we aim to show that if the initial data
belongs to $\dot H^\frac12$ to guarantee the local existence, then some extra
weak space which is subcritical, is sufficient to prove the global
well-posedness. More precisely, we prove that if the initial data belongs to
$\dot{H}^{1/2}\cap \dot{W}^{s,1}$ for $12/13<s \leqslant 1$, then the
corresponding solution exists globally and scatters.
