A hybrid "optical tweezers-micro Raman spectroscopy" technique is introduced in this letter. Applying this system,the micro-Raman spectrums of rat erythrocyte and saccharomyces cerevisiae in vivo were obtained. The results show that this technique can obviously improve signal-to-noise ratio compared with conventional approaches. Besides,the damage from lasers on the cells were analyzed. It was revealed that the damage of cell from intense IR laser were much lower than that from the weak Ar+ laser. Finally,the system was also applied in carbon nano-tube (CNT) analysis and Raman spectra from CNT were obtained.