Introduction one of the major problems in using the plant resources of the world’s fl ora is the introduction of the greenhouse plants because a large number of cultivated plants used by mankind, as well as indoor plants are native to tropical and subtropical countries. The family Cactaceae is one of the largest groups of higher plants, which comprises over 3000 species, and in the greenhouses of Botanical Garden (Institute) it is the best represented - about 800 taxa. The collection of cacti of Botanical Garden (Institute) has a unique value for the Republic of Moldova. Material and methods The collection of plants of the family Cactaceae of Botanical Garden (Institute) served as study material. The phenological observations on plant growth and development were carried out according to „Методика фенологических наблюдений в ботанических садах СССР” (1975). The scientifi c inventory of the collection is performed yearly. The critical processing of the taxa is performed according to Backeberg (1979), Copăcescu (2001). Results and discussions In the Botanical Garden (Institute) of ASM over about 40 years, it was created the collection of plants of the family The Cactaceae, comprising 805 taxa, distributed in 131 genera, representing the 3 subfamilies: Pereskioideae, Opuntioideae and Cereoideae (Backeberg, 1979; Copăcescu, 2001,). The subfamily Cereoideae is the best represented numerically - with 120 genera and 734 taxa, it is followed by Opuntioideae - with 7 genera and 64 taxa and Pereskioideae - 4 genera and 7 taxa. Regarding the number of taxa in the genus, the following picture appears: Mammillaria Haw. – 186; Opuntia Mill. – 41; Lobivia Britt et Rose – 31; Gymnocalicium Pfeiff.- 30 ; Rhipsalis Gaerth. – 28; Echinocereus Engelm. – 25; Coryphantha Lem. – 21; Astrophytum Lem. – 19; Notocactus Berger – 19; Neochilenia Baskeb. – 18; Ferocactus Britt et Rose – 17; Parodia Speg. – 16; Rebutia Schum. – 15; Cleistocactus Lem. – 14; Aylostera  Speg. – 14; Dolichotele Britt et Rose – 12; Trichocereus Riccob. -12 etc. 415 (51.6%) taxa reach the generative phase and 283 (35.2%) taxa fructify. The period of fl owering of cacti lasts, practically, the whole year, but the most taxa bloom in spring-summer. In order to get qualitative seeds, the fruits are harvested when they are well ripened, usually from autumn until spring. Conclusions 1. The Botanical Garden (Institute) of the ASM has a collection of plants of the family Cactaceae with a unique value for the Republic of Moldova created over about 40 years, which currently comprises 805 taxa, distributed in 131 genera, representing the three subfamilies: Pereskioideae, Opuntioideae and Cereoideae. 2. The collection of cacti of Botanical Garden (Institute) serves as didactic and illustrative material for the didactic and instructive activities of secondary school pupils, high school pupils, students and master’s degree students.