Background : Hemoglobin is one of erythrocyte tetrameric proteins that binds to a non-protein molecule, the iron porfin compund called heme. Decrease of hemoglobin level can cause insufficient blood flow and carrying oxygen from the lungs to the body, so the impact is on the difficult to concentration, decreased physical endurance, and decrease of activity that makes easily tired. Adolescent do the physical activity to make their body fit should have regular exercise in daily activity like walking or cycling. In addition quality of physical education supports children to develop behavioral patterns that will keep them physically active throughout their lives. Sports and recreational facilities provide an opportunity for everyone to exercise Purpose : The aim of this research is to know the correlation between hemoglobin level with activity patterns in girl adolescent at SMP Muhammadiyah 2 Yogyakarta. Methods : This research used non-experimental with cross sectional design and used kuantitative methode. Sample in this research was 76 people which consist of girl adolescent at SMP Muhammadiyah 2 Yogyakarta with simple random sampling. Data analysis using spaerman rank. Results : 52,6% respondent’s had abnormal category in hemoglobin level. 50% respondent’s had moderate category in activity patterns. Correlation result from spearman rank test, p = 0,982 (p>0,05). Conclusion : There is no correlation between hemoglobin level with activity pattern in girl adolescent.