A phosphorylcholine group-containing chemical compound represented by the following formula (1). In this formula, m denotes 2-6 and n denotes 1-4. X.sub.1, X.sub.2, and X.sub.3, independent of each other, denote a methoxy group, ethoxy group, or halogen. Up to two of X.sub.1, X.sub.2, and X.sub.3 can be any of the following groups: a methyl group, ethyl group, propyl group, isopropyl group, butyl group, or isobutyl group. R is one of the structures in the following formulas (2)-(4) (the chemical compound of formula (1) in the structures of the following formulas (2)-(4) is expressed as A-R--B). In formulas (2)-(4), L is 1-6, P is 1-3. Also a surface modifier consisting of the aforementioned phosphorylcholine group-containing chemical compound, modified powder treated with said surface modifier, a chromatography packing consisting of a modified carrier treated with said surface modifier, a filter treated with said surface modifier, and a glass device treated with said surface modifier.