a ring $r$ is strongly clean provided that every element in $r$ is the sum of an idempotent and a unit that commutate. let $t_n(r,sigma)$ be the skew triangular matrix ring over a local ring $r$ where $sigma$ is an endomorphism of $r$. we show that $t_2(r,sigma)$ is strongly clean if and only if for any $ain 1+j(r), bin j(r)$, $l_a-r_{sigma(b)}: rto r$ is surjective. furt...