In ubiquitous environments, situation-awareness is a desirable property to support adaptive and personalized services. To describe situation-awareness effectively, a situation-aware interface description language (SA-IDL) which can express a collaboration system with various contexts and actions is researched. However, conflicts can occur when services expressed in SA-IDL collaborate with each other, though each service does not make any errors. This is because each service is described with requirements for each one. So, in order to provide situation-aware services without inconsistency, conflicts among services should be identified and resolved. In this paper, we propose a mathematical modeling of SA-IDL to identify the conflicts among situation-aware services, and suggest conflict resolution graph model to identify the services which occur the conflicts. Also we proposed the resolution algorithm based on weight.