In order to save the searching cost of passive target location in two-dimension planes,a smallest enclo- sing rectangle problem for randomly-deployed WSN (Wireless Sensor Network) nodes is investigated.Firstly,a smallest enclosing rectangle planning method for WSN nodes,which makes anchors continuously approach target nodes with the depth-first searching strategy,is proposed on the basis of Boolean search.Then,a coordinate max- min algorithm is put forward to compute the minimum enclosing rectangle according to aforementioned anchors’lo- cation.The results of both simulation and algorithm analysis show that the proposed strategy possesses less computa- tion complexity than such searching strategies as traversal methods for smallest enclosing rectangle and circle,and helps obtain the enclosing rectangle with minimum area more precisely.