InAs self-organized quantum dots (QDs) and quantum dashes (QDHs) grown on GaAs (100), (211)B and (311)B substrates by molecular beam epitaxy at different growth temperatures (T s ) have been investigated. QDs were observed after deposition of 2ML 1 0 0 (or 4ML 3 1 1 ) of InAs on GaAs (100) (or (311)B) at T s ranging from 450 o C to 530 o C. The average density decreases and the average size increases monotonically with increasing T s . QDs with bimodal size distribution were formed when 6ML 2 1 1 of InAs was deposited on GaAs (211)B at lower T s . When the same amount of InAs was deposited at higher T s , however, QDHs were observed. The photoluminescence intensity of the QDs and QDHs showed similar temperature dependence, whereas the excitation density dependence showed quite different behaviors.