The invention provides PCR (polymerase chain reaction) primers, method and kit for analyzing genetic diversity in gramineous plants. According to the technical scheme provided herein, 3 DNA templates different in character are picked from 13 DNA parts, 21 pairs of primers with clear polymorphic bands are screened out of 100 pairs of primers, the 21 pairs of primers are used to mark the 13 DNA parts, electrophoresis, imaging, photographing and data statistics are performed, UPGMA (unweighted pair-group method with arithmetic means) cluster analysis is performed on genetic similarity and genetic distances of the plants, and diversity analysis and interspecific relation research are performed. The research indicates that gramineous plant germplasm resources show rich genetic diversity; the genetic groups of these materials have no great relationship with geographic origin and geographic environment; SRAP (sequence-related amplified molecular polymorphism) marker is a molecular marker suitable for the research on gramineous plant germplasm resources.