Abstract: Mobile query works in heterogeneous network environment based on wireless and wired network, whose communication link error rate is higher, and susceptible to interference and interruption.Real-time and high availability are required in mobile query.After comparing and analyzing the existing algorithms, in this paper based on the previous study about directed diffusion, integrating agent technology, the directed selecting mobile agent algorithm named DSMA is proposed.Finally, the experiments represent that the network delay of the proposed algorithm is higher than traditional mobile agent algorithm at low load, but at high load condition the delay is lower.Moreover, the speed of querying using DSMA algorithm is faster.Meanwhile, during the querying with DSMA, the energy differences between WSN nodes can be balanced and the overall life of network is improved.