Abstract: Provided are methods of increasing yield, biomass, growth rate, vigor, oil content, abiotic stress tolerance and/or nitrogen use efficiency of a plant by expressing within the plant an exogenous polynucleotide comprising a nucleic acid sequence at least 80% identical to SEQ ID NO: 905, 882, 1-12, 15-105, 203-297, 299-523, 845-881, 883-904, 906-925 or 933; or an exogenous polynucleotide encoding a polypeptide at least 80% identical to SEQ ID NO: 172, 146, 106-117, 120-145, 147-171, 173-202, 524-616, 621-844, 926-931 or 932. Also provided isolated polynucleotide comprising a nucleic acid sequence selected from the group consisting of SEQ ID NOs:905, 882, 1-13, 15-105, 203-523, 845-881, 883-904, 906-925 and 933, which can be used to increase yield, biomass, growth rate, vigor, oil content, abiotic stress tolerance and/or nitrogen use efficiency of a plant.