Abstract: A small-scale, home-made computer system for searching the mass spectra of indole alkaloids has been built up which consists of a data file and a set of searching subroutines. Included in this system are:(1) A data file involving 1600 mass spectra of indole alkaloids taken from literature and (partly) measured in our laboratory in the abbreviated form after Biemann , i. e. , picking 2 peaks out of every 14-mass interval within the whole range of the spectrum.(2) A search program capable of executing fingerprint match as well as spectra comparison approached in different manners: molecular weight, molecular formula, selected ion peaks and selected neutral losses.(3) The out-put of results is given in the form of numerical tabulation or bargraphs as requested by the user. The data file can be modified easily by deleting or renewing modules.