The purpose of this thesis is to fabricate the quantum dot waveguide and measure electro-optic (EO) modulation characteristics. We focus on the refractive index change (£Gn), phase retardation, and electro-optic coefficients for quantum dot samples. The £fg=1.3£gm InGaAs quantum dot structures were grown on n+ GaAs substrates by MBE. We design a series of 2.2£gm straight and slope 7¢X single mode waveguide, and use the cleavage surface method to produce Fabry-Perot cavity. In fabrication process, we first defined the device pattern by using photo-lithography technique. Second, we etched ridge waveguide by using dry etching or multi-step wet etching method. Finally, we used the etching solution HBr:HCl:H2O2:H2O=5:4:1:70 to smooth the sidewall and reduce the scattering loss. We analyzed the quantum dot EO properties by measuring phase retardation of Fabry-Perot resonance at different bias. From measuring the Fabry-Perot resonance at£f=1515nm TE-polarization, the linear electro-optic (LEO) and quadratic electro-optic (QEO) coefficients of C311 sample are 7.26¡Ñ10-12m/v and 1.14¡Ñ10-18m2/v2 , respectively. And the LEO and QEO coefficients of C251 sample are 2.99¡Ñ10-11m/v and 4.10¡Ñ10-17m2/v2, respectively. By coupling £f=1515nm TM-polarized light, we found the main influence of C251 sample is Kerr effect, and the QEO coefficient is 3.52¡Ñ10-17m2/v2. Both electro-optic coefficients are significantly larger than those measured in quantum wells and bulk GaAs. These results are applicable to QD-based low drive voltage and small size modulators.