An optoelectronic analog-to-digital conversion(ADC) approach based on optical time division multiplexing(OTDM) is proposed.The time division multiplexing of optical signal is realized by employing only one continuous wave laser and an electro-optic modulator combined with fiber delay lines(FDLs),and the analog-to-digital conversion is completed through electronic ADCs.The system structure is simple and has good scalability.The ratio of signal to noise and distortion(SINAD) as high as 28.5 dB,which is equivalent to 4.44 effective number of bits(ENOB),is obtained in two-channel OTDM ADC experiments.The main causes of quantization error are analyzed and the methods to improve precision are discussed.