Recent commissioning of the Cooler Storage Ring at the Heavy Ion Research Facility in Lanzhou (HIRFL-CSR) has allowed us for direct mass measurements at the Institute of Modern Physics in Lanzhou (IMP), Chinese Academy of Sciences. A series of isochronous mass measurements have been carried out in the past few years using Kr-78, Kr-86, Ni-58, and Sn-112 beams. The main results and the present status are presented in this talk, and the implications of these results with respect to nuclear structures and nucleosynthesis in the rp-process of x-ray bursts are discussed.