Abstract: (Joint with Shaoyun Bai) I will talk about our recent work on defining integral curve counting invariants for general symplectic manifolds. The original idea was due to Fukaya-Ono using the natural stable complex structure on the moduli spaces. The most important technical ingredient is a rigorous formulation of the transversality condition proposed by Fukaya-Ono for orbifolds. As applications, we defined integer-valued Gromov-Witten invariants and proved the Arnold conjecture over integers.