Salak (Salacca edulis), commonly known as snake fruit, is one of Indonesia's local fruit preference with a promising commercial prospect for the development of horticultural product. This fruit is a superior fruit commodity of Padang Sidempuan which has been recognized nationally. A significant change of geographical altitudes from lowland to highland supported the salak growth when planted in South Tapanuli. This study was aimed to evaluate the phenotypic variability as well as its correlation of salak planted in three different subdistricts of South Tapanuli representing low, mid and highlands. Sampling was conducted using purposive sampling method where 30 accessions of salak were collected from all those three subdistricts in South Tapanuli. Both qualitative and quantitative traits were statistically analyzed and evaluated for its phylogenetic using NTSYS 2.02. According to the phylogenetic analysis, 37 morphological traits resulted in a similarity coefficient ranging from 0.34-0.68. Of all accessions tested, two accessions (MC4 and MC5) were closely clustered with a coefficient of 0.68. Moreover, 7 traits were positively correlated to sugar content, including plant height,number of fruit bunch, length and width of leaflet, number of leaf, fruit weight and flesh thickness.