We study the electronic and optical properties of InAs/InP quantum dots ??QDs?? on ??100?? and ??311??Bsubstrates. Atomic force microscopy ??AFM?? and cross-sectional scanning tunneling microscopy ??X-STM?? areused to define the size and shape of the quantum dots for calculations. Eight-band k·p calculations includingstrain and piezoelectric effects are then performed on such a structure for two different kinds of substrateorientation ??311??B and ??100??. Results for several QD heights found on ??311??B substrate fit well the experimentaldata obtained from photoluminescence measurements. On ??311??B substrate, the shear and hydrostaticdeformations are found to be enhanced compared to those on ??100?? substrate thus affecting the electronic andoptical properties. The ??311??B QDs are found to activate second-order ??S-P channels?? transitions resulting fromthe complete loss of symmetry due to the presence of the piezoelectric field.