With its unique time-frequency characteristics and integrated advantages, micro combs have gradually become the cornerstone of modern information system. Recently, all fiber microcavity combs made a progress. Researchers from the University of Electronic Science and Technology of China and Nanjing University realized the generation of laser, Kerr and Brillouin optical frequency combs by using ultra-high Q-value fiber Fabry Perot resonators. They demonstrate unique advantages such as low loss, dynamic tunability and ultrahigh stability, may play new potentials in timing-standard, communication, microwave and sensing applications for fiber systems.