Title: Holonomy filtration and knots Abstract: Motivated by the construction of the isomorphism between Heegaard Floer and Seiberg--Witten Floer homologies (joint with Yi-Jen Lee and Clifford H. Taubes), I will describe a doubly filtered Floer homology for null-homologous knots in closed oriented 3-manifolds in the context of Seiberg-Witten theory. I will also explain how the aforementioned construction leads to an isomorphism between the latter and Ozsvath-Szabo's knot Floer homology.