This paper investigates a multi-unmanned aerial vehicle (UAV) enabled wireless communication, where a number of ground nodes (GNs) are scheduled to communicate with UAVs in the presence of jammers with imperfect location information. Considering different quality of service (QoS) requirements for a wide range of applications, we aim to improve the minimum throughput, the average throughput, and the delay-constrained minimum throughput of all GNs, respectively, via the joint design of UAVs' trajectories, GNs' scheduling and power allocation. However, the formulated optimization problems are difficult to solve due to the non-convex and combinatorial nature. To overcome this difficulty, we propose two block coordinate descent (BCD) based algorithms to solve them sub-optimally with the aid of slack variables, successive convex approximation (SCA) technique and S-procedure. Numerical results show that our proposed algorithms outperforms the benchmark algorithms and offers a considerable gain in the view of different QoS requirements, giving a certain practical significance. INDEX TERMS UAV communications, trajectory optimization, anti-jamming, robust design, QoS requirement. egy of the UAV was proposed to enhance the system performance. However, without providing sequential trajectory, [25] and [26] explored little facility of UAV's maneuverability and flexibility. Thus, by taking spatial retreats into account, in [27] and [28], a trajectory optimization algorithm was investigated to combat jamming signals where the UAV would fly away from the jammers while executing communication tasks. In [29], the UAV's trajectory and communication resources were jointly designed to guarantee the coexistence with the jamming signals from the terrestrial D2D GNs. Nevertheless, these works assumed that jammers' location was perfectly known. Though a robust optimization method was studied in [30], where one UAV needed to maintain the communication quality in the presence of an adversarial jammer with uncertain location information, however, considered little about the joint optimization of trajectory and communication resources for multiple UAV. Particularly, in the multi-UAV enabled communication, the communication resources allocation for various UAV-GN pairs need to be tackled. In [31], a joint trajectory, power allocation and user scheduling algorithm was applied to mitigate the interference of system users. In [32], the UAV to UAV communication was investigated via joint trajectory and power optimization wherein the UAVs shared the same frequency. In [33] and [34], orthogonal frequency division multiple access (OFDMA) mode and time division multiple access (TDMA) mode were applied to avoid the interference of system users, respectively. Consequently, with the possible interference caused by system users, the jamming attacks from a adversarial jammer is more challenging in the multi-UAV enabled communication and has not been fully investigated. Moreover, wireless communication systems have gradually evolved to aim not only for hig...