Protected areas have been continually challenged among the special-use forests. An example is the Hon Can forest station, Xuan Lien Nature Reserve, Vietnam. This paper describes the patrol routes and the responsibility of a patrol ranger to record harm to the forest using the Geographic Information System. The Global Positioning System tracks the areas with the highest potential for illegal activities which had drastic negative effects on biodiversity conservation established along the patrol routes. The results illustrated six common patrol routes with 61 coordinate points and 14 types of illegal activity encounters. Interestingly, the illegal activity was not statistically significant among the patrol routes. Furthermore, the patrol distance had a higher efficiency than patrol time in each patrol route. Locally, it requires further planning of such patrols in the foreseeable future. Furthermore, the number of illegal activities regularly changed if the patrol personnel focused on recording only the longterm period.