In this work, we prepared zwitterionic-catechol conjugates. Atom transfer radical polymerization (ATRP) was employed to produce multiple-catechol initiators or catechol-g-zwitterionic polymers with controlled molecular weights. Bindings of these zwitterionic-catechol conjugates to various self-assembly monolayer (SAM) surfaces terminated with CH3, OH, COOH, NH2 have been studied to reveal binding mechanisms. Results are compared with those from bare gold surfaces. Protein adsorption from a single protein solution or blood serum/plasma onto these surfaces grafted with zwitterionic groups was tested by a surface plasmon resonance (SPR) sensor. Results show excellent nonfouling properties of these modified surfaces. Effects of multi-catechol anchor, buffer, ionic strength and temperature on the adhesion were also investigated. This work demonstrates a new, convenient and efficient way for surface modification to achieve ultra low fouling.