The nature of happiness and its factors is one of the significant discussions in happiness psychology.  According to psychologists, happiness includes two affective and cognitive dimensions.  Positive  psychology  with  a  concentration  on  the  cognitive  dimension,  brings  up  subjective welfare  and  self-taught  happiness.  Concerning the requirement  of  meaning  in  life  and  the  role  of  goal  from one  side,  and  extremist  attention  to  happiness  from  the  other  side,  schools  such as  Lamaism  introduce  happiness  as  a  goal  and  meaningful  factor.  In  religious  area  the  nature  of  happiness  in  verses  of  the Qur`an  and  traditions  is  also  very  obvious  dividing  the  happiness  into  true  and  untrue  ones  with  emotional  and  spiritual  levels,  in  contradistinction  to  psychological  approach.  The  study  of  relationship  of  religion  with  life  meaning  as  well  as   kind  of  life  meaningfulness  in  Islam,  gives  as  explanation  of  the  relationship  between  happiness  and  meaningfulness .Due  to  Islam happiness  and  meaningfulness  in  two  places  of  the  first  and  the  last,  are  introduced. As a  result,  happiness  in  Lamaism  is  an  essential  goal  while  Islam  regards  happiness as a secondary goal which is caused by life meaningfulness .utilizing from achievements  of  both  Islam  and  psychology  about  happiness  is  necessary. 

Key words:  nature of happiness, life meaningfulness, Islam, positive psychology.