The effect of substitution pattern of the linear-type π-conjugated oligothiophenes is examined. The material solubility, thermal properties, and charge transport characteristics of two hexyl subsituted quinquethiophenes (DH5T) were determined along with the characteristics of an organic field-effect transistor (OFET). The solubility of 4,7-bis (3’-hexyl-2,2’-bithiophene-5-yl) thiophene (β-DH5T), which featured a lateral substitution, was significantly better than that of α,α’-dihexylquinquethiophene (α-DH5T) by altering the directional position of the alkyl group, which makes it a good candidate for solution-processed OFETs. Despite the well-defined vertical alignment of α-DH5T, the hole mobility of the β-DH5T film (3.02 × 10–3 cm2 V–1 s–1) was one order of magnitude higher than the hole mobility of the α-DH5T film (2.47 × 10–4 cm2 V–1 s–1) prepared by solution processing.