Island of Lošinj, as a part of geotectonic zone of Adriatic, was formed by transgression in Pleistocene. In geomorphological terms Cres and Lošinj archipelago are part of Učka, the southern extension of Ćićarija mountain ridges which parts are submerged. The island extends in typically Dinaric NW-SE direction. At the narrowest point it is separated in northern and southern part by artificial canal Privlaka. The northern part, which is the object of research, has an area of 52,4 km2 and it consists of hilly mountain ridge Osoršćica and two flattened parts - loess plateau in the southwest and krast plateau on the northeastern part of the island. The flattened parts represent submerged krast plateau remains. Most of the studied area is made of Cretaceous limestone and dolomite, Tertiary limestones and Quaternary fine grain sand. Conducted geomorphological analysis in this paper includes morphometric, morphogenetics and morphographic relief features. In the studied area the following morphogenetic relief types are detected: krast, fluviokrast, slope, marine, loess and anthropogenic relief. Geomorphological map of the northern part of the island represents the geomorphological synthesis of this study.