KNU corn breeding team in collaboration with International Corn Foundation (ICF) is dedicated to develop super corn hybrids for developing countries like Nepal and Cambodia. The team works to develop high bio-energy maize hybrids for Korea. Crossing of temperate with tropical germplasm shows new heterotic patterns. Four tropical inbred lines from IITA, Nigeria, ten sub-tropical lines from Nepal and two temperate lines (P45 and 69B) from Korea were crossed to produce single-cross hybrids. Besides, four single-cross hybrids from Nepalwere crossed with P45 and 69B to produce three-way crosses. Gray leaf spot (Cercospora zea-maydis) being the most important problem of corn in mid-hills of Nepal, GLS resistant materials from IITA were crossed with Nepal materials in Cambodia to produce GLS tolerant hybrids. Single-cross hybrids were evaluated at ICF Agriculture Center in Cambodia and KNU farm, Gunwi in Korea in 2008. The three-way crosses were planted at Gunwi farm and the GLS resistant materials were planted at Khumaltar station of Nepal Agricultural Research Council, Kathmandu. Crosses of Tzi-25 with RML-4 and RL-111 and RL-105xNML-2 were found outstanding in Cambodia. Four tropical x subtropical hybrids (Tzi-18xRML-4, Tzi-18xRL-14, Tzi-25xRL-14 and RL-47xTzi-25), four temperate x subtropical hybrids (P45xRL-111, P45xRML-8, RML-5x69B and 69BxRL-105). P45xGaurab was the most suitable for both grain and biomass production.