The low P content available in most Brazilian soils is a limiting factor to normal growth and productivity of crops. So, for increase of crops productivity are used high levels of chemical phosphate fertilizers, which raise the cost and can lead to environmental damages. Phosphate solubilizing microorganisms representing an source of phosphorous alternative to chemical fertilizers, thus, this study aimed to carry out the genetic improvement of phosphate solubilizing fungus Penicillium pinophilum by mutagenesis approach with ultraviolet radiation and methyl methanesulfonate (MMS) chemical agent. For mutagenesis assays, P. pinophilum was inoculated on NBRIP-BPB medium and incubated at 25 °C for 7 days. After growth, the spores were homogenized in saline solution (0.9%) containing Tween 80 (0.01%). The spores were counted in a Neubauer chamber and solution was adjusted to 10⁸ spores/mL.Aliquots of 1 mL of spore suspension were used for each treatment: different times of exposures to 15 W UV radiation lamp (30, 60, 90 and 120 seconds) and different concentrations (4.8 mM, 9.1 mM and 16.7 mM) of methyl methanesulfonate (MMS). After 30 min of exposure at 25 °C, MMS was removed by spore washing with saline solution. Control non-mutated was used and all experiment was done in triplicate. For counting and screening, spores of each treatment were plated in triplicate in NBRIP-BPB. According analysis, exposures of P. pinophilum to 120s of UV and 9.1 mM of MMS were effectives and resulted in 1% of survival of spores. About of 421 colonies were screened and 17 mutant colonies showed solubilization indices above the wild strain. In conclusion, classical mutagenesis techniques can provide strains of P. phinophilum with high potential for phosphorous solubilization for use as biofertilizer in agriculture.