Research related to optical tweezers has been awarded the Nobel Prize for physics in 1997 and 2001, respectively. It greatly promotes the development of physics, life science & medicine and nanotechnology. Due to its small size and the capability of non-contact manipulation of particles and biological samples, optical fiber tweezers have been attracted much attention in recent years. Supported by National 985 Fund, our lab has a series of high-standard equipment for microscopic imaging and spectral analysis, including scanning electron microscope (SEM), optical microscopes, Raman spectroscopy, high resolution optical spectrum analyzer (OSA), fiber tapering equipment, etc. We mainly focus on integrating optical tweezers with optical fiber sensors for investigating biological samples, e.g., living cells. Recently, graded-index fiber based optical tweezers have been investigated both theoretically and experimentally, see Optics Express, 21, 16181 (2013). We are also collaborating with Cancer Institute and Hospital of Sichuan to do research on optical trapping or stretching and detection of cancer cells.