An information processing system searching a literature database for a literature, comprising: a database including pathway information related to a metabolic pathway that at least includes information on, for each of a plurality of metabolic reactions, a compound produced by reaction, a compound used in reaction, and enzymes that act in the metabolic reaction; an input unit (101, 102) configured to receive an input of information on a first reaction compound which was produced by reaction, a first reaction compound which was used in reaction, and a first enzyme that acts in the metabolic reaction for literature search, as pathway information of metabolic reaction for literature search; an extraction unit configured to extract, based on the information on the first reaction compound which was produced by reaction, the first reaction compound which was used in reaction, and the first enzyme, pathway information that has a predetermined relationship with the pathway information of metabolic reaction for literature search from the database, and extract, from the extracted pathway information, information on a peripheral compound that is different from the first reaction compound which was produced by reaction and the first reaction compound which was used in reaction; and a search unit configured to search the literature database for a literature based on the pathway information of metabolic reaction for literature search and the information on the peripheral compound wherein information related to an input metabolic pathway represented by a directed graph in which a compound that is a reaction compound in a metabolic reaction is set as a node, and an enzyme that acts when a node used in reaction is moved to a node produced by reaction is set as an edge is input, and a search expression is generated only based on information on the compound and enzyme related to the input metabolic pathway so as to search the literature database for a literature, characterized in that the peripheral compound is extracted as a compound of a node whose distance on a graph represented by the extracted pathway information with a node of the input metabolic pathway on the graph is smaller than a predetermined threshold value. a database including pathway information related to a metabolic pathway that at least includes information on, for each of a plurality of metabolic reactions, a compound produced by reaction, a compound used in reaction, and enzymes that act in the metabolic reaction; an input unit (101, 102) configured to receive an input of information on a first reaction compound which was produced by reaction, a first reaction compound which was used in reaction, and a first enzyme that acts in the metabolic reaction for literature search, as pathway information of metabolic reaction for literature search; an extraction unit configured to extract, based on the information on the first reaction compound which was produced by reaction, the first reaction compound which was used in reaction, and the first enzyme, pathway information that has a predetermined relationship with the pathway information of metabolic reaction for literature search from the database, and extract, from the extracted pathway information, information on a peripheral compound that is different from the first reaction compound which was produced by reaction and the first reaction compound which was used in reaction; and a search unit configured to search the literature database for a literature based on the pathway information of metabolic reaction for literature search and the information on the peripheral compound wherein information related to an input metabolic pathway represented by a directed graph in which a compound that is a reaction compound in a metabolic reaction is set as a node, and an enzyme that acts when a node used in reaction is moved to a node produced by reaction is set as an edge is input, and a search expression is generated only based on information on the compound and enzyme related to the input metabolic pathway so as to search the literature database for a literature, characterized in that the peripheral compound is extracted as a compound of a node whose distance on a graph represented by the extracted pathway information with a node of the input metabolic pathway on the graph is smaller than a predetermined threshold value.