The present study aimed to investigate the bioactive compounds present in the sea cucumber Holothuria parva of Bushehr coast with emphasis on biological properties of lectin. The presence of compounds such as: alkaloids, phenols, saponins, flavonoids, glycosides, fatty acids and amino acids was confirmed by aqueous crude extract. Carbohydrate, phenolic and protein levels were also measured which were 121.41, 104.82 and 210.33 µg / ml, respectively. The lectin was extracted from Sea cucumber and then precipitated with ammonium sulfate, then isolated by dialysis bag with a molecular weight cut-off of 12 kDa and tested on 6 bacterial strains. The results showed that this type of lectin had no effect on the growth inhibition of the target bacteria and its insecticidal rate on Tenebrio molitor larvae was moderate, as well as the lectin was tested on human blood (i.e.B ) and defective sheep blood group, which showed that this type of lectin has blood agglutination and hemolytic properties.The obtaind results from the one-dimensional electrophoresis apparatus as well as functional groups and amino acids from the Foureir-transform- infrared spectroscopy (FT-IR) have shown that lectin is present in this species. Experiments were also performed to evaluate free radical scavenging by 1-1, diphenyl-2-picryl hydrazyl (DPPH) method. The results demonstrated that with increasing the concentration of sea cucumber crude extract, the percentage of free radical scavenging increased and there was a significant correlation between the concentration of crude extract and the inhibition percentage of free radicals were present (P <0.05). According to the results of this study, H. parva species have important and effective bioactive compounds that could be used in the medical and pharmaceutical industries, therefore more investigations regardings its critical applications should be carried out.