Abstract. In order to solve the integer optimization problem and improve the search efficiency of GPS ambiguity resolution, in view of the problem characteristics, an integer artificial fish swarm algorithm (IAFSA) is introduced to solve the problem of integer ambiguity resolution. The algorithm added the integer constraints to the classical AFSA and adopted a attenuation factor to adjust the visual field and step length of the artificial fish adaptively. According to the simulation results, compared with the genetic algorithm (GA), the IAFSA can get integer ambiguity solution quickly, and has the higher search efficiency and reliability.