GaP/InP short period superlattices (SLs) are grown on GaAs (311)A substrates by gas source molecular beam epitaxy (MBE). Scanning tunneling microscopy/spectroscopy (STM/STS) measurements show that the quantum dot (QD) structures are self-formed with a lateral density of 10(11) cm(-2). Growth temperature dependence of self-formed structures is studied with STM/STS and clear temperature dependence is observed. Optimum growth temperature is about 460 degrees C. Time-resolved photoluminescence (PL) spectroscopy measurement on the multilayer QD (MQD) structures shows that the PL decay time strongly depends on emission energy and temperature, and ranges from 0.1 to 2.5 ns, which can be explained by considering the tunneling effect of carriers between QDs.