Development of a prototype of a portable optical sensing system is presented for fast detecting of samples' fluorescence spectra. A compact configuration is achieved by integrating a small spectrometer, a microcontroller, a Universal Serial Bus (USB) Host Shield, a network module, and a web server. The fluorescence spectra of a tested sample can be obtained. Then the test data are sent through network communication to our Cloud Server which can store the data for further analyses. With this configuration, test results can be revealed in a short time and downloaded by users to their laptops, tablets or cellphones anytime and anywhere.