There may be times when links to your website can actually hurt your Google ranking. The ideal way to resolve this problem is to contact the owner or webmaster of the offending site and request that your link be removed, or at least be updated to include the nofollow link attribute.
Obviously, this will not always be possible, so Google has an advanced feature called “Disavow Links” which allows you to, well, disavow any (exceedingly negative) links that you may wish. You should use this tool with caution, as a misuse could relatively easily impact your web rankings in a negative way. Used properly, however, it can restore or prevent negative impacts from unwanted sources.