In order to improve the speed and lower the cost of the monolithic integ rated optical receiver for large core(1mm)plastic optical fiber (POF) communication,the structure and p erformance of large photosensitive surface photodetector (PD) and subsequent amplifying circuit based on silicon are investigated.Firstly,based on the standard CMOS process,the model of N+/N-well/P-sub PDs structure is established and optimized.The PD′s characteristics of optical spec tral responsivity and frequ ency response are simulated.Then,the collaborative design and simulation are accomplished through combining the estab lished PD′s equivalent circuit model with the designed subsequent amplifying circuit.Finally,by using the 0.5μm CMOS process,the single PD with size of 200μm×200μm,and the monolithic integrated circuit of PD and p ost amplifiers are packaged and tested,respectively.The tested results indicate that at the wavelength of 650nm,the responsivity of N+/N-well/p-sub PD is 0.12A/W,the dark current is about 9pA,under the bias v oltage of －2.5V.The sensitivity of the monolithic integrated optical receiver is －23dBm under the bit-error-rat e (BER) of 10－9.And a clear eye-diagram wit h the speed of 250Mbit/s is achieved.The designed monolithic integrated optical receiver can be applied to 250Mbit/s optical fiber communication systems very well.