A polymer compound includes i) a polymerization unit represented by —(CHR³—CR⁴(-L¹-Y¹))_x—(CHR⁵—CR⁶(-L²-Y²))_y—; and ii) a silane coupling group represented by —S—(CH₂)_n—Si—(R¹)_m(OR²)_3-m, as a terminal of the polymer, wherein R¹, R², R³, R⁴, R⁵, R⁶, n, x, y, L¹, L², Y¹ and Y² are defined in the specification. A lithographic printing plate base includes: a support; and a hydrophilic layer containing solid particles to a surface of which a hydrophilic polymer is chemically bonded.