This paper describes the applications which are used to automate the analysis of encoded combinatorial libraries. Commercial packages from MDL, Oracle and Agilent are linked with application software written in C/C++, in Microsoft Access and in ChemStation macro language. Encoding correspondence lists for each of up to three synthetic steps are conveniently associated with building block lists using the first application, CodeGen. The second application Decode allows the user to identify the individual beads picked onto a 96-well plate and the pool number for each bead. The decoding chromatography data for each well is then loaded into the program. The chromatography data is used to identify the tags used in the synthesis. Along with the building block information from ISIS/Host, the building block used in each step of the synthesis can be identified. A third routine, Code-to- Structure, takes the coded library building blocks and creates the connection table in ISIS for each structure found by the decode program. For quality control of encoded library synthesis, the decoded structures on a set of beads is compared to the LC/UV/MS data for the ligand cleaved from the same bead. CAPTURE, a GlaxoSmithKline proprietary application, is used to display and analyze the decoded structures and associated mass spectral data. This application uses simple isotopic composition and electrospray ionization rule sets to predict mass spectra and judge the concordance of a structure- mass spectrum data set. An ancillary program, EIC, is used to extract predicted single ion chromatograms from the full scan LC/MS data.