The Supreme Judicial Court has posted the 2010 edition of the Massachusetts Guide to Evidence.  Although this is a Guide, rather than formal rules of evidence, it is compiled by a Supreme Judicial Court Advisory Committee.  The Introduction notes that the Guide "organizes and states the law of evidence applied in proceedings in the courts of the Commonwealth, as set forth in the Federal and State Constitutions, General Laws, common law, and rules of court." 

A link to the guide can also be found in the Research and Litigation section of this website, in the document entitled Massachusetts Legal Materials -- Links.