Lubeg (Syzygium lineatum (D.C. Merr. & L.M. Perry) which belongs to the family Myrtaceae is commonly found in the Cagayan Valley region, particularly in first district of Cagayan, Philippines. Thirteen (13) existing long grown tree at Cagayan State University at Lal-lo Campus were evaluated. Identification, morphological characterization of the tree, leaf, fruit and seed was preliminarily evaluated, to include the tree's yield potential in September to October fruiting season. A grown fruiting tree of Lubeg in Cagayan is erect, with an average height of 11.307 and ranging from 6.30- 12.25 meters with a canopy spread of 7.63 meters or ranging from 6.0 to 12.5 meters. The leaves are elliptical in shape measuring about 9-12cm in size with entire margin and generally with acute leaf apex. The ripe fruits are very dark reddish purple berry, glubose to cherry-like in shape with white pulp/flesh, while the half- ripe fruits are pinkish to red berry in color. The fruit weight is ranging from 1.2 to 6.9 grams with an average diameter of 2.95cm and ranging from 2.1cm to 4.1cm. The pulp or flesh of the fruit is sour to very sweet seed depending to its variety. The edible portion/pulp per fruit is 77% in terms of weight with one dicot seed. The tree is an endemic plant of Lal-lo, Cagayan. The tree bears fruits twice a year, in the months of July and October, respectively. A Lubeg tree has an average yield potential of 48.88kg per tree per harvest. The ripe fruit is traditionally eaten raw, used for wine and vinegar making and considered by the rural folks as a good source of nutrients and potential source of income of Cagayanos, Philippines.