Abstract: Laser devices used in the field of optical-electronics are made of GaAs, InP and so on, which are expensive and hard to be integrated into Si-chip. If a laser device can directly made from silicon, the problems can be solved. A novel strategy for preparing large-area, vertically aligned silicon nanotip arrays at near room temperature by combining silver mirror reaction with metal-catalyzed electroless etching (MCEE) has been developed. It has been demonstrated that the silicon nanotips arrays with a length among 4~7 m and a middle part diameter ranging from 100 to 300 nm have been successfully fabricated on silicon wafers. This method is considerably simple, efficient, nontoxic, controllable and low-cost. Moreover it does not need high temperature, complicated equipments and demanding conditions of environment. At last, the field emission property of the Si nanotip array is primarily tested. The conclusions are as follows: effective electron emission can be obtained by the Si nanotip array; the turn-on field is 2.7 V/m (the current density is 10 A/cm2). The field enhancement factors determined using the F-N curve is 692, the resultant large-area vertically aligned Si nanotips arrays on Si substrate can be expected to be used on field-emitting applications in the future and it will have broad prospects for development.