Abstract　 　 
Understanding the chemical composition and evolution of disks thus provides constraints on the nature of molecules incorporated into planetesimals and planets.The disk chemical evolution is predicted to depend on radiationfields, temperature and density structures. Molecular emissioncan be used to investigate how the disk physics drives the disk chemistry, and how the disk chemistry traces the disk physics. I will summarize our observational understanding of the chemistry in disks from observations made with the Submillimeter Array (SMA) and describe our empirical model approach to interpret the spatially resolved molecular emissions by constraining the radial and vertical distribution of molecular abundances. Such analysis provides the essential framework for characterizing the disk chemical processes, which aids in understanding the physical and chemical evolution during planet formation.