OsMKK is a mitogen kinase gene family located in the middle reaches of rice MAPK pathway, which mainly undertakes the functions of upstream signal convergence and gradual downward diffusion and transmission. Their functions in rice growth and stress response are still unclear. Abiotic stresses such as drought, low temperature and salt damage are important factors affecting rice yield. In this paper, the structure of OsMKK gene family was analyzed by bioinformatics, and its possible biological functions were predicted. Taking indica rice variety 93 1 1 as material, rice seedlings were subjected to low temperature, high temperature, salt stress, H2O2, ABA, JA and SA stress. The changes of physiological indexes of rice seedlings under seven treatments and the expression pattern of OsMKK gene family were determined. Finally, their possible biological functions are discussed. The main results are as follows: Chromosome location, phylogenetic tree and gene structure analysis of 1. The research of OsMKK shows that eight members of OsMKK gene family are located on four different chromosomes, which are divided into four subclasses: A, B, C and d 2. The first class has three genes: OsMKK 1, OsMKK6, OsMKK3, with multiple introns and exons, and various regulatory forms. The second category includes five genes: OsMKK4, OsMKK5, OsMKK 10- 1, OsMKK 10-2 and OsMKK 10-3, and contains only one exon. The subdomain and motif analysis of OsMKK showed that the gene family contained 1 1 subdomain, ATP binding site and phosphorylation site. Except OsMKK 10- 1, osmkk 10-2, OsMKK 10-3, they all contain S/T XXXXX S/T motifs. 2. Cis-acting elements on the promoter of 5'- terminal ATG region of 2.osmkk gene family. Such as low temperature reaction element, thermal shock reaction element, dehydration reaction element, ABA reaction element, JA reaction element and defense reaction element. Each gene contains many different cis-acting elements, which may be related to many adverse reactions. The changes of physiological indexes of rice leaves under 3.7 treatments showed that the changes of relative conductivity, malondialdehyde and proline content were consistent. With the extension of stress time, the relative conductivity increased (except ABA treatment); The content of malondialdehyde increased in different degrees; Proline content also showed an upward trend (except JA treatment). The results showed that with the extension of stress time, the cells of rice seedlings were damaged more and more. The expression of 4.4. OsMKK gene family has obvious induction characteristics under 12℃ low temperature, 38℃ high temperature, 250 mM salt, 10mMH2O2, 50μM ABA, 50μM JA and 1 mM SA stress. At the low temperature of 12℃, the expression of OsMKK4 did not change at 0- 12 h, but was induced at 24 h; At 38℃, the expression of OsMKK3 was activated at 3 h and then decreased. The expression of OsMKK4, OsMKK5 and OsMKK6 was the strongest at 6 h, and then decreased. The expression of other genes increased slightly at 6 h; Under 250 mM salt treatment, the expression of OsMKK3 was induced at 1h and reached the highest level. Under the treatment of 10 mM H2O2, the expressions of OsMKK4, OsMKK5 and OsMKK 10-2 were instantaneously induced in 1h, and reached the highest level, then decreased. Under the treatment of 50μM ABA, the expressions of OsMKK4 and OsMKK5 were induced at 1h; Under the treatment of 50μM JA, the induced expression of OsMKK4 was the strongest, and it increased with time. Followed by OsMKK5, the expression increased at 1 h and then stopped increasing; Under the treatment of 1mMSA, the expression of OsMKK6 was induced within 6 hours and reached the highest level. All kinds of adversity have little effect on the expression of other genes. The expression of 5.5. OsMKK in stem, leaf, leaf sheath and young panicle of rice is different. The expression of OsMKK 1 in stem is low, and other genes are expressed in all four tissues. The expression level of OsMKK 10-2 in four tissues is not high, and other genes are high and low in four tissues.