This research aims at (1) describing students' environmental knowledge based on local potency in West Nusa Tenggara Province, (2) analyzing students' environmental knowledge in terms of gender, and (3) analyzing students' environmental knowledge in term of level or grade. This survey research is analyzed descriptively and inferentially using t test. The subjects consisted of 431 Senior High School students around West Nusa Tenggara Province. The research instrument uses questionnaire consisting of 5 positive and negative statements with 4 scales namely Strongly Agree (SS), Agree (S), Disagree (TS), and Strongly Disagree (STS). The results showed that (1) there were 27.3% of students who had environmental knowledge in the low category, 40.6% sufficient category and 32% high category, (2) there was a different value of environmental care between male and female students (Sig<.05) in the mean score of 70.21 and 66 respectively; and (3) there was a different in the environmental care scores of students in grades 10 and 11 (Sig<.01) in the average of 73.09 and 64.45. Thus, the findings indicate the importance of introducing local potency based on environmental insights to increase students' environmental knowledge.