Earthquake emergency response requires different number of teams to cooperate with each other and coordinate their activities to achieve global objectives. Coordination is the key challenging problem that field teams face in urban search and rescue (USAR) emergency response because of the geographic and uncertain environment. Therefore, it is necessary to optimize coordination of teams by allocating tasks to teams in time and space efficiently and sufficiently. The present paper aims to propose an efficient approach that allows humans to collaborate with coordinator assistant agents to assign tasks to teams. To achieve this purpose, we did the following stages: (1) the structure of the USAR task force and environment characteristics were analyzed, (2) we analyzed the spatial coordination problem and then modeled it, (3) features and properties of required approach were assessed, (4) we designed a contract net based model for distributed spatial task allocation and proposed the architecture of spatially distributed intelligent assistant agents (SpDI2A), and (5) finally, our approach was implemented and validated in a geospatial simulation which was developed using AnyLogic software and Java programming. The final result composes of 10 features satisfying the features of the required system. © 2011 IEEE.