In this study, we report the synthesis of bimetallic FePt nanoparticles (NPs) on FTO substrate and their application as efficient counter electrodes (CEs) in dye-sensitized solar cells (DSCs). To overcome disadvantages related with conventional method, the synthesis of alloy NPs is carried out by dry plasma reduction. Bimetallic FePt NPs were synthesized on the FTO surface with the volume ratios of precursors as follows: 1:9, 2.5:7.5, 5:5, 7:3, 9:1. The CEs were denoted as Fe₀Pt₁, Fe_0.1Pt_0.9, Fe_0.25Pt_0.75, Fe_0.5Pt_0.5, Fe_0.7Pt_0.3 and Fe_0.9Pt_0.1. The highest efficiency was 8.93% for Fe_0.25 Pt_0.75 CE, which is higher than that of device employing Pt NPs CE. The results are contributed by high electrical conductivity and excellent catalytic activity of FePt alloy CEs. The obtained results suggest that the tailoring of electronic structure of Fe _x Pt_1-x (1 ≥ x ≥ 0) alloy can be used for enhancing the catalytic activity of CE, and in turn for construction of high-efficiency DSCs.