Polarization and modal birefringence of elliptical-core two-mode fibers are investigated. Wavelengths corresponding to zero group delay difference (GDD) between the two spatial modes and between the orthogonal polarizations are computed when the fiber parameters, i.e., the relative core/cladding index difference and the ratio of major over minor axis, are varied. Simple relationships between the zero GDD wavelengths and fiber parameters are obtained. With proper fiber design, zero GDD between the two spatial modes and the two orthogonal polarizations can be achieved at the same wavelength. Lightwave Technol. LT-5, 1041LT-5, -1044LT-5, (1987. 16. Masashi Eguchi, Masanori Koshiba, "Accurate finite-element analysis of dual-mode highly elliptical-core fibers," J. Lightwave Technol. 12, 607-613 (1994). 17. Robert L. Gallawa, I. C. Goyal, Yinggang Tu, and Ajoy K. Ghatak , "Optical waveguide modes: an approximate solution using Galerkin's method with Hermite-Gauss basis functions," IEEE J. Quan. Electron. 21, 518-522 (1991). 18. Tzong-Lin Wu, and Hung-chun Chang, "An efficient numerical approach for determining the dispersion characteristics of dual-mode elliptical-core optical fibers," J. Lightwave Technol. 13, 1926Technol. 13, -1934Technol. 13, (1995 194-197 (1993). 21. C.D. Poole, J.M. Wiesenfeld, D.J. Digiovanni, and A.M. Vengsarkar, "Optical fiber-based dispersion compensation using higher order modes near cutoff," J. Lightwave Technol. 12, 1746-1758 (1994). 22. Wang Zhi, Ren Guobin, Lou Shuqin, Liang Weijun, "Investigation of the supercell based orthonormal basis function method for different kinds of fibers," Opt.