Cotton is one of the important crops of Pakistan and is attacked by many chewing and sucking pest. Chemical insecticides are used abundantly to suppress the pest population. The use of host-plant resistance is an alternative tool to control cotton insect-pests. The current research was aimed to identify the cotton physio-morphological marker to manage pressure of sucking pests such as jassid (Amrasca bigutulla bigutulla Ishida), thrips (Thrips tabaci Lind.) and whitefly (Bemisia tabaci Gen.) on cotton. To this end, the present research was conducted on various cotton varieties classified on the basis of their genetic characteristics such as nectard (CIM-554, CIM-557and MNH-786), nectariless (Stoneville-701, Stoneville-697, and Stoneville-857), high gossypol (CIM-496 and LAHG 1838-1488) and gossypol free (Greeg-25-V and 3-508 OP), Bt-703 and standard cotton variety (CRIS-342). The incidence of sucking pest on cotton was recorded fortnightly. The physio-morphic characters (density and length of trichome on lamina, midrib and vein, gossypol glands on midrib and lamina) of above mentioned cotton varieties were correlated with the incidence of sucking pest. Result revealed that cotton varieties had significantly different physio- morphic characters. There was a negative and significant correlation of TDM (Trichome density on midrib), (r-value = -0.615) and TDV (Trichome density on vein) (r-value = -0.574) with jassid population, while TDL (Trichome density on lamina), TDM and TDV was positively and significantly correlated with whitefly population. Stepwise regression analysis revealed that TDM, TDL and GGL (Gossypol gland on lamina) contributed 27.5%, 33.9% and 36.6% in population variation of jassid, whitefly and thrips, respectively. High TDM and TDV was considered morphological marker for jassid while low TDL, TDM and TDV was thought of as morphological marker for whitefly. The cotton variety 3-508 OP having relatively less dense but long TLL (Trichome length on lamina), TLM (Trichome length on midrib) and TLV (Trichome length of vein) showed highest host-plant resistance level against jassid and thrips, while Bt variety Bt-703 with relatively less TDL, TDM, TDV, TLL, TLM and TLV exhibited highest resistance against whitefly, hence recommended for farmer field cultivation and as base material in cotton breeding to produce cotton varieties resistant against sucking pest.