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We select from Paper I a sample of 306 massive star clusters observed withthe Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) in thevicinity fields of M31 and M33 and determine their metallicities, ages andmasses. Metallicities and ages are estimated by fitting the observed integratedspectra with stellar synthesis population (SSP) models with a pixel-to-pixelspectral fitting technique. Ages for most young clusters are also derived byfitting the multi-band photometric measurements with model spectral energydistributions (SEDs). The estimated cluster ages span a wide range, fromseveral million years to the age of the universe. The numbers of clustersyounger and older than 1 Gyr are respectively 46 and 260. With ages andmetallicities determined, cluster masses are then estimated by comparing themulti-band photometric measurements with SSP model SEDs. The derived massesrange from $\sim 10^{3}$ to $\sim 10^7$ $M_{\odot}$, peaking at $\sim 10^{4.3}$and $\sim 10^{5.7}$ $M_{\odot}$ for young ($< 1$ Gyr) and old ($>1$ Gyr)clusters, respectively. Our estimated metallicities, ages and masses are ingood agreement with available literature values. Old clusters richer than[Fe/H] $\sim -0.7$ dex have a wide range of ages. Those poorer than [Fe/H]$\sim -0.7$ dex seem to be composed of two groups, as previously found forGalactic GCs -- one of the oldest ages with all values of metallicity down to$\sim -2$ dex and another with metallicity increasing with decreasing age. Theold clusters in the inner disk of M\,31 (0 -- 30 kpc) show a clear metallicitygradient measured at $-0.038\pm0.023$ dex/kpc.

The LAMOST spectroscopic survey of star clusters in M31. II. Metallicities, ages and masses