The multimode optical waveguides are fabricated using epoxy resin mat erials,and the non-contact lithography is adopted as a simple and cost-effective process.A kind of reliable and efficien t developer and corresponding developing time are found by a lot of experiments .and The effects of temperature and humidity,and spin-coating process on the wa veguides thickness were studied;the effect of transparent portion width of lithography mask,the spacing between lower claddin g layer and lithography mask,exposure intensity and time on the width of the optical waveguides are also studied.The morphology of the samples is observed by scanning electron microscopy (SEM),and the fabricated ridge optical waveguide s with cross sectional size of approximately 50μm×50μm have smooth surfaces and vertical sidewalls.The tra nsmission loss of epoxy resin multimode optical waveguides at wavelength of 850nm is measured to be 0.1dB/c m by cut-back method.Taking account of the high temperature shock on optical wa veguide during optoelectronic in tegrated process,the thermal stability of the fabricated optical waveguides is tested and the attainable highest thermal stab ility temperature is 210℃.