This paper proposes a two-level dynamic load balancing scheme for grid and distributed systems. We focus on reducing average task response time. In order to achieve the goals, efficient dynamic load balancing is required. What make difficult dynamic load balancing are decisions such that how much loads are migrated, and to which nodes the loads move. We simplified task immigration through pairwise immigration based on two load thresholds scheme. We compare the proposed scheme with HDLA algorithm proposed by B. Yagoubi et al. Experiments show that our algorithm reduces average response time to about 3% compared to that of HDLA algorithm.