Capparis spinosaCapparis spinosa (caper bushCaper bush), is a xerophytic and perennial winter-deciduous species. This species grows naturally in Europe, Africa, Madagascar, Asia, Australia and Oceania from sea level to an altitude of 1900 m. Caper is called the Plant of the Millennium with diverse economic and medicinal values. This species is used as a medicinal plantMedicinal plants contained numerous beneficial compounds, including alkaloidsAlkaloids, glucosinolatesGlucosinolates, carotenoidsCarotenoids, polyphenolsPolyphenols, fatty acidsFatty acids, streroidsStreroids, terpenoidsTerpenoids, vitamin CVitamin C, tocopherolsTocopherols and mineralsMinerals. This species is an important source of flavonoidsFlavonoids such as quercetinQuercetin, rutinRutin and kaempferolKaempferol. Immature flower buds, semi-mature fruits and young shoots with small leaves are used as food or condiment. Caper is propagated by seedsSeed, stem cuttings and grafting. The growing market demand, difficulty in caper propagation and limited area under cultivationCultivation have led to overharvesting of the wild caper for domestic uses and trades that have made this species at risk of geneticGenetic erosionGenetic erosion. Therefore, the conservationConservation of geneticGenetic resourcesGenetic resources and developing new varietiesVarieties of caper would require the improvementImprovement of current conventional and innovative biotechnological techniques. In this chapter, we represent information concerning taxonomicTaxonomic approaches, the origin and distribution, characterization and conservationConservation of geneticGenetic resourcesGenetic resources, crop cultivation practicesCultivation practices, recent developments in biotechnologyBiotechnology and molecular biology as well as their application for crop improvementImprovement in association with conventional breedingConventional breeding methods of caper.