Unsafe industrial and domestic waste disposal causes surface water contamination and different health problems in many developing countries like Ethiopia. To tackle the pollution problem research based mitigation method is highly needed. Therefore, this study was aimed to analysis Cyprus papyrus wastewater treatment efficiency in glass fiber constructed wetlands under different density. Total 12 glass fiber wetlands were constructed with dimensions of 1.5m length, 1.5m width and 0.8m depth. Four treatments unplanted (control), planted with low (61), medium (84) and high (125) density of Cyprus papyrus with three replication were used under the same gravel and sand substrate. The data were analyzed using SPSS version 20. The treatment beds were irrigated with wastewater sourced from Bahardar city administration. The result showed that the average above ground dry biomass of Cyprus papyrus in low, mid and high density treatment beds were 9.0ton/ha, 12.27ton/ha and 15.82ton/ha in 14 weeks growing period respectively. Except temprature, the analysis of variance showed a significant difference at (p<0.01) among the treatments. The removal efficiency of high density Cyprus papyrus BOD, TSS, TDS, turbidity, TA, SC, PO43-, NO3- and ammonia were 68.4%, 63.7%, 19.9%, 83.5%, 34.2%, 36.2%, 75.6%, 21.2% and 88.5%, respectively during five days duration of wastewater in the glass fiber constructed wetland had significant difference at 0.01. And also the removal efficacy of heavy metals Cu, Cr, and Zn were 66%, 45.8%, and 66.1% respectively in effluent from high density Cyprus papyrus had significant difference at 0.01. Density of plant directly proportional to pH and DO and inversely proportional to other parameters whereas, temperature was found under oscillation relationship. Thus, Cyprus papyrus reduced substantially the concentrations of most physicochemical parameters and heavy metals. Finally, wastewater treatment by using Cyprus papyrus could be encouraged in Ethiopia. Keywords: wastewater, Cyprus papyrus, constructed wetland, nutrients and heavy metals