Study of STM-excited light emission (STML) from organic films is significant for the potential applications to organic photoelectronics devices in nanometer scale. In this note, practical tips for measurements are given, focusing on how to detect very weak light signals efficiently. The mechanism of STML from molecules is described, and the technique of surface-plasmons enhanced molecular fluorescence is utilized for observation of intense light emission at far field regions. Provided are experimental results of STML from spin cast organic films of porphyrin series such as H2TBPP, H2TPP and PhTPP and conjugate polymer MEH-PPV under atmospheric conditions as well as in UHV as the examples.