In order to investigate the spatial heterogeneity of phosphorus (P) in the litter of natural Picea jezoensis var. microsperma (Lindl.) W.C.Cheng & L.K.Fu and Abies nephrolepis (Trautv.) Maxim. mixed forest and associated factors, four 1 hm² permanent plots were established for litter collection and surveyed for stand structure in northeastern China. A total of 400 litter samples from the semi-decomposed layer were collected using an equidistant grid point sampling method. The spatial variation in litter P concentration, return, and use efficiency were analyzed using geostatistics. The results showed that the average litter P concentration was 1.26 g/kg, the average P return was 24.57 kg/hm², and the average use efficiency was 841.74. The variation in P concentration, return, and use efficiency in the four plots was moderate, and the degree of variation showed that P return > P use efficiency > P concentration in an individual plot. Litter P concentration, return (the nugget-to-sill values in plots Ⅲ and IV were >75%, indicating that their spatial heterogeneity was mainly caused by random effects and they were not suitable for interpolation), and use efficiency showed high spatial autocorrelation, primarily resulting from structural factors. The spatial heterogeneity of P use efficiency was lower than that of P concentration and return, and the spatial autocorrelation ranges of P concentration, return, and use efficiency in the plots were 9.9-40.5 m, 11.9-52.9 m, and 8.1-39.3 m, respectively. Within plots, the fractal dimension of P use efficiency was higher than that of P concentration, with a more complex spatial pattern, while P concentration showed stronger spatial dependence with better spatial structure. Litter P concentration, return (except plots Ⅲ and IV), and use efficiency in the four plots showed strip and patch gradient distribution, and the spatial variation of P concentration was similar to that of P use efficiency. Litter P concentration, return, and use efficiency were influenced by canopy density, species, plant diversity, and other factors.