In this talk, I will discuss the cosmological analysis of the Dark Energy Survey Year 3 (DES Y3) redMaPPer galaxy cluster’ sample. The DES Y3 data is based on optical/near-infrared imaging covering ~5000 square degrees of the Southern sky taken from August 15, 2013, to February 12, 2016, by the Dark Energy Camera mounted on the 4-m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. The DES Y3 sample contains ~22,000 clusters having richness greater than 20 in the redshift range 0.2<z<0.7, and shear measurements for ~100M sources. For this analysis, we combine the cluster abundance and the tangential shear measurements around clusters (N+γT) to constrain cosmology and the observable-mass relation simultaneously. We also present the prospects for constraining cosmology with a combination of the cluster abundance with multiwavelength data (N+multi-λ) and the recently developed method of combining the abundance with galaxy clustering, cluster tangential shear and cluster clustering (N+4x2pt). Due to the wide redshift range probed by the survey and these complementary methodologies, we can place competitive constraints on the amplitude of the matter fluctuations and the matter density of the large-scale structure.