The coalition, headed by the JMM, has 44 MLAs in the 81-member Assembly.
Leading the pack is Shibu Sorens JMM, 17 of whose 18 MLAs have criminal cases against them, National Election Watch (NEW) said on the basis of affidavits of the elected legislators.
The only JMM MLA who has no criminal case against her is Sita Soren, daughter-in-law of Shibu Soren and widow of Durga Soren.
The BJP and AJSU have eight and four MLAs respectively with criminal cases against them. One JD(U) legislator and the lone JJM legislator also have criminal cases against them, NEW said.
JMMs Dumri MLA Jagannath Mahato is booked in 14 criminal cases while Sorens son Hemant, the newly elected MLA from Dumka, has six cases against him, it said.
BJPs Jharkhand unit president and a strong contender for the deputy chief ministers post, Raghubar Das, also has criminal cases against him.
Among BJP MLAs, Ranchi legislator CP Singh has nine cases against him.
Eleven of the 14 Congress MLAs also have cases against them while eight JVM(P) legislators and four RJD MLAs have cases against them.
Shibu Soren is all set to take oath as chief minister heading a five-party coalition in Jharkhand on Wednesday, which will be the seventh dispensation in nine years since it became a separate state. Soren, who was asked to take the floor test of his government by January 8, has not yet revealed who else would be taking oath along with him triggering speculation.