Tory leader David Cameron said small firms would get £2,000 cash bonuses to take on apprentices while there would be extra college places for under-25s.
Speaking in Cornwall, he said he would cut business taxes, help firms to recruit staff and make "work pay".
Labour say the Tories will scrap existing help for the youth unemployed.
They say the Conservatives would abolish the Future Jobs Fund, which aims to provide 200,000 work or training opportunities for people aged between 18 and 24 who have been out of the job market for a year.
'Economically inactive'
Mr Cameron said tackling unemployment was the "most important issue" facing the next government.
"As we stand today, we have got one in four adults economically inactive, 900,000 young people not in education, not in employment, not in training," he said.
