PURPOSE: To obtain the subject polymer having excellent safety and selectivity and useful as a raw material for electrically conductive polymer, heat-resistant polymer, etc., under mild condition in high yield and efficiency by polymerizing a specific silicon compound in the presence of a group 8 transition metal complex.

CONSTITUTION: This organic polymer composed of the recurring unit of formula II and having a molecular weight of 500-100,000 is produced by polymerizing a silicon compound of formula I (A is bivalent organic group) such as 1,4-bis(trihydrosilyl)butane in the presence of a group 8 transition metal complex containing ruthenium, etc., as the central metal atom.