Abstract: The present invention provides a conjugated diene polymer containing a low vinyl portion having a vinyl content of 2 to 20% by mol and a high vinyl portion having a vinyl content of 50% by mol or more, and a method for producing the same; a rubber composition containing a rubber component containing the conjugated diene polymer, at least one filler selected from the group consisting of carbon black and silica, a silane coupling agent, and a crosslinking agent; crosslinked rubber prepared by crosslinking the rubber composition; and a rubber product and a tire containing the crosslinked rubber. The tire can achieve both the abrasion resistance and the low fuel consumption capability, the conjugated diene polymer, the rubber composition, and the crosslinked rubber are preferred for producing the tire, and the rubber product is excellent in abrasion resistance and low heat generation property.