  In this paper, we prove a pseudolocality-type theorem for $\mathcal
L$-complete noncompact Ricci flow which may not have bounded sectional
curvature; with the help of it we study the uniqueness of the Ricci flow on
noncompact manifolds. In particular, we prove the strong uniqueness theorem for
the $\mathcal L$-complete Ricci flow on the Euclidean space. This partially
answers a question proposed by B-L.~Chen.
