The outstanding botanical researcher, academician Vahid Jalal oglu Hajiyev started working as a senior researcher at the Institute of Botany of the Azerbaijan Academy of Sciences in 1952, in 1957-1958 he was the deputy director of the Botanical Garden, in 1957-1972 he was the deputy director for scientific affairs of the Institute of Botany. In 1972-1973, he was the director of the Scientific Research Institute of Forage, Grassland and Pastures of the Ministry of Agriculture of Azerbaijan. From 1972 to the end of his life, he worked as the head of the Geobotany Department at the Institute of Botany of the Azerbaijan Academy of Sciences, in 1978-1988 as the deputy director for scientific affairs, and in 1988-2008 as its director.
V.J. Hajiyev defended his candidacy in 1952, doctoral theses in 1966, and received the scientific title of professor in 1970. He was elected a corresponding member of the Azerbaijan Academy of Sciences in 1983, and a full member in 1989.
V.J. Hajiyev conducted geobotanical research on the high mountain meadows of the Greater and Lesser Caucasus, as well as Azerbaijan, paying special attention to the problems of flora systematics, vegetation cover, useful plant resources, rare and endangered plant species. V.J. Hajiyev actively participated in floristic, systematic and other expeditions organized in different years, especially in the "Gunesh-84" and "Gunesh-85" experiments, and scientifically proved the regularity of the location of plant formations. He gave a new systematic analysis of 85 species of 25 genera in 5 chapters for volumes V-VIII of the multi-volume fundamental work "Flora Azerbaijan". V.J. Hajiyev is the author of more than 230 scientific works, including 12 monographs.
Under the leadership of V.J. Hajiyev, 5 doctoral theses and about 40 candidate theses were defended.